CN116702647B - A method and device for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure - Google Patents

Abstract

The present application discloses a method and device for calculating vortex-induced vibration of an attached-rotating combined cylindrical structure, the method comprising determining the distance between each control rod and the cylinder based on a preset gap ratio and the diameter of the cylinder, and establishing a combined vortex-induced vibration numerical model; dividing the combined vortex-induced vibration numerical model, determining the fluid region from the combined vortex-induced vibration numerical model, and calculating the flow field characteristics of the fluid region based on preset fluid parameters; determining the force parameters of the cylinder based on the flow field characteristics, and calculating the velocity parameters of the cylinder based on the force parameters; obtaining the motion parameters of the cylinder based on the velocity parameters and the angular velocity of rotation, and outputting the motion parameters of the cylinder. By setting a combined structure of a control rod and a cylinder, the vortex-induced vibration suppression of the cylinder under the combined action of rotation and control rods can be explored, and then a structure that effectively suppresses vortex-induced vibration can be obtained, providing a basis for the analysis of the vortex-induced vibration mechanism and response characteristics of marine risers.

Description

A method and device for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure

Technical Field

The present application belongs to the field of marine engineering technology, and in particular relates to a method and device for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure.

Background Art

The marine riser system is an important structure in marine engineering, which undertakes important functions such as oil and gas transportation. When the ocean current passes through the marine riser, alternating vortex shedding will occur. Vortex shedding will cause periodic vibrations in the riser structure, namely vortex induced vibration (VIV). In the response process of vortex induced vibration, the structural surface excitation force generated by vortex shedding will induce structural vibration, and the vibration of the structure will affect the fluid vortex shedding and thus affect the excitation force. This is a typical nonlinear fluid-solid coupling problem. When the vibration frequency of the structure is close to its natural frequency, it will cause the locking phenomenon (lock-in) of the structural vibration frequency, stimulating a high amplitude response of the structure. Since vortex induced vibration can easily induce high amplitude and high excitation force responses of cylinders, and even cause structural fatigue damage, the suppression method of vortex induced vibration of cylinders has received widespread attention.

In existing research, vortex-induced vibration suppression is generally achieved by affecting the flow field near the cylinder, such as control rods, splitter plates, spiral strips and applied rotation, etc. However, for existing cylindrical vortex-induced vibration suppression technology, its suppression effect is significantly affected by the inherent properties of the flow field and structure, and even enhances the vortex-induced vibration. Secondly, existing research is mainly based on the suppression characteristics of cylindrical vortex-induced vibration by a single structure, but the suppression effect of a single structure on cylindrical vortex-induced vibration is unstable and easily affected by the flow field and the cylinder's own properties, and even the structure strengthens the vortex-induced vibration response of the cylinder.

Summary of the invention

This application aims to solve the above-mentioned problem that the suppression effect of the existing cylindrical vortex-induced vibration suppression technology is significantly affected by the inherent properties of the flow field and the structure, and even enhances the vortex-induced vibration. Secondly, the existing research is mainly based on the suppression characteristics of a single structure on cylindrical vortex-induced vibration, but the suppression effect of a single structure on cylindrical vortex-induced vibration is unstable and easily affected by the flow field and the properties of the cylinder itself. The structure even enhances the vortex-induced vibration response of the cylinder and other technical defects. A vortex-induced vibration calculation method and device for an appendage-rotating combined cylindrical structure are proposed, and its technical solution is as follows:

In a first aspect, an embodiment of the present application provides a method for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure, comprising:

The distance between each control rod and the cylinder is determined based on a preset gap ratio and the diameter of the cylinder, and a combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; wherein the ratio of the distance between each control rod and the cylinder to the diameter of the cylinder is the preset gap ratio;

The combined vortex-induced vibration numerical model is divided, a fluid region is determined from the combined vortex-induced vibration numerical model after the division process, and a flow field characteristic of the fluid region is calculated based on preset fluid parameters;

Determine the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculate the velocity parameters of the cylinder based on the force parameters;

The motion parameters of the cylinder are obtained according to the speed parameters of the cylinder and the preset rotation angular velocity, and when it is detected that the motion parameters of the cylinder meet the preset conditions, the motion parameters of the cylinder are output.

In an optional solution of the first aspect, the at least two control rods are specifically three control rods;

According to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods, a combined vortex-induced vibration numerical model is established, including:

A reference triangle is established based on the center of the cylinder and the diameter of the cylinder; wherein the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder;

Adjust the distance from each vertex of the reference triangle to the center of the inscribed circle according to the distance from each control rod to the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance from each control rod to the cylinder, and use the position of each vertex in the adjusted reference triangle as the relative position between each control rod and the cylinder;

Determining the diameter of each control rod based on the preset diameter ratio and the diameter of the cylinder;

A combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the relative position between each control rod and the cylinder, and the diameter of each control rod.

In another optional solution of the first aspect, the combined vortex-induced vibration numerical model is divided and processed, including:

In the combined vortex-induced vibration numerical model, the center of the cylinder and the center of each control rod are determined respectively;

Divide a region whose distance from the center of the cylinder is within a preset first distance interval as a first rigid region;

Dividing a region whose distance from the center of each control rod is within a preset second distance interval as a second rigid region;

Divide the area whose distance from the center of the cylinder is within a preset third distance interval as a dynamic grid area;

The area of the combined vortex-induced vibration numerical model excluding the first rigid area, the second rigid area and the dynamic grid area is divided into a static grid area.

In another optional solution of the first aspect, a fluid region is determined from the combined vortex-induced vibration numerical model after the division process, and a flow field characteristic of the fluid region is calculated based on preset fluid parameters, including:

All regions except the first rigid region and the second rigid region in the combined vortex-induced vibration numerical model after the division process are used as the initial fluid region;

Based on the preset boundary conditions, the initial fluid region is clipped to obtain the target fluid region;

According to the target fluid region and preset fluid parameters, the flow field characteristics of the fluid region are calculated.

In yet another optional solution of the first aspect, determining the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculating the velocity parameters of the cylinder according to the force parameters, includes:

The surface pressure load of the cylinder is extracted from the flow field characteristics of the fluid region;

The pressure load in the downstream direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the downstream direction in the fluid area;

The pressure load in the cross-flow direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the cross-flow direction in the fluid area;

Substitute the fluid force of the cylinder in the fluid region in the downstream direction and the fluid force of the cylinder in the fluid region in the cross-stream direction into the preset dynamic equation;

The dynamic equations are discretely calculated based on the preset solution parameters to obtain the velocity parameters of the cylinder.

In yet another optional solution of the first aspect, when it is detected that the motion parameters of the cylinder meet a preset condition, outputting the motion parameters of the cylinder includes:

Draw an amplitude curve based on the motion parameters of the cylinder, and determine whether there is a curve showing periodic changes in the amplitude curve;

When it is detected that there is a curve showing periodic changes in the amplitude curve, it is determined that the motion parameters of the cylinder meet the preset conditions, and the motion parameters of the cylinder are output.

In another optional solution of the first aspect, after obtaining the motion parameter of the cylinder according to the speed parameter of the cylinder and the preset rotation angular velocity, the method further includes:

When it is detected that the motion parameters of the cylinder do not meet the preset conditions, the cylinder and each control rod are controlled to move based on the motion parameters of the cylinder, and the fluid area is updated;

Based on the preset fluid parameters, the flow field characteristics of the updated fluid region are calculated, and the motion parameters of the cylinder are recalculated according to the flow field characteristics of the updated fluid region.

In a second aspect, an embodiment of the present application provides a vortex-induced vibration calculation device for an appendage-rotating combined cylindrical structure, comprising:

A model building module, used to determine the distance between each control rod and the cylinder based on a preset gap ratio and the diameter of the cylinder, and to establish a combined vortex-induced vibration numerical model according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; wherein the ratio of the distance between each control rod and the cylinder to the diameter of the cylinder is the preset gap ratio;

The first calculation module is used to divide the combined vortex-induced vibration numerical model, determine the fluid area from the combined vortex-induced vibration numerical model after the division process, and calculate the flow field characteristics of the fluid area based on the preset fluid parameters;

The second calculation module is used to determine the force parameters of the cylinder in the fluid area based on the flow field characteristics of the fluid area, and calculate the velocity parameters of the cylinder according to the force parameters;

The parameter output module is used to obtain the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotation angular velocity, and output the motion parameters of the cylinder when it is detected that the motion parameters of the cylinder meet the preset conditions.

In an optional solution of the second aspect, the at least two control rods are specifically three control rods;

The model building module includes:

A reference triangle is established based on the center of the cylinder and the diameter of the cylinder; wherein the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder;

Adjust the distance from each vertex of the reference triangle to the center of the inscribed circle according to the distance from each control rod to the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance from each control rod to the cylinder, and use the position of each vertex in the adjusted reference triangle as the relative position between each control rod and the cylinder;

Determining the diameter of each control rod based on the preset diameter ratio and the diameter of the cylinder;

A combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the relative position between each control rod and the cylinder, and the diameter of each control rod.

In yet another optional solution of the second aspect, the first computing module includes:

In the combined vortex-induced vibration numerical model, the center of the cylinder and the center of each control rod are determined respectively;

Divide a region whose distance from the center of the cylinder is within a preset first distance interval as a first rigid region;

Dividing a region whose distance from the center of each control rod is within a preset second distance interval as a second rigid region;

Divide the area whose distance from the center of the cylinder is within a preset third distance interval as a dynamic grid area;

The area of the combined vortex-induced vibration numerical model excluding the first rigid area, the second rigid area and the dynamic grid area is divided into a static grid area.

In yet another optional solution of the second aspect, the first calculation module further includes:

All regions except the first rigid region and the second rigid region in the combined vortex-induced vibration numerical model after the division process are used as the initial fluid region;

Based on the preset boundary conditions, the initial fluid region is clipped to obtain the target fluid region;

According to the target fluid region and preset fluid parameters, the flow field characteristics of the fluid region are calculated.

In yet another optional solution of the second aspect, the second computing module includes:

The surface pressure load of the cylinder is extracted from the flow field characteristics of the fluid region;

The pressure load in the downstream direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the downstream direction in the fluid area;

The pressure load in the cross-flow direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the cross-flow direction in the fluid area;

Substitute the fluid force of the cylinder in the fluid region in the downstream direction and the fluid force of the cylinder in the fluid region in the cross-stream direction into the preset dynamic equation;

The dynamic equations are discretely calculated based on the preset solution parameters to obtain the velocity parameters of the cylinder.

In yet another optional solution of the second aspect, the parameter output module includes:

Draw an amplitude curve based on the motion parameters of the cylinder, and determine whether there is a curve showing periodic changes in the amplitude curve;

When it is detected that there is a curve showing periodic changes in the amplitude curve, it is determined that the motion parameters of the cylinder meet the preset conditions, and the motion parameters of the cylinder are output.

In yet another optional solution of the second aspect, the device further comprises:

After obtaining the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotational angular velocity, when it is detected that the motion parameters of the cylinder do not meet the preset conditions, the cylinder and each control rod are controlled to move based on the motion parameters of the cylinder, and the fluid area is updated;

Based on the preset fluid parameters, the flow field characteristics of the updated fluid region are calculated, and the motion parameters of the cylinder are recalculated according to the flow field characteristics of the updated fluid region.

In a third aspect, an embodiment of the present application further provides a vortex-induced vibration calculation device for an appendage-rotating combined cylindrical structure, comprising a processor and a memory;

The processor is connected to the memory;

A memory for storing executable program codes;

The processor runs the program corresponding to the executable program code by reading the executable program code stored in the memory, so as to implement the vortex-induced vibration calculation method of the appendage-rotating combined cylindrical structure provided by the first aspect of the embodiment of the present application or any one of the implementation methods of the first aspect.

In a fourth aspect, an embodiment of the present application provides a computer storage medium, which stores a computer program. The computer program includes program instructions. When the program instructions are executed by a processor, the method for calculating the vortex-induced vibration of the appendage-rotating combined cylindrical structure provided in the first aspect of the embodiment of the present application or any one of the implementation methods of the first aspect can be implemented.

In the embodiment of the present application, for the riser set in the sea, when calculating the vortex-induced vibration value of the appendage-rotating combined cylindrical structure, the distance between each control rod and the cylinder can be determined based on the preset gap ratio and the diameter of the cylinder, and a combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; the combined vortex-induced vibration numerical model is divided, and the fluid area is determined from the combined vortex-induced vibration numerical model after the division process, and the flow field characteristics of the fluid area are calculated based on the preset fluid parameters; the force parameters of the cylinder in the fluid area are determined based on the flow field characteristics of the fluid area, and the speed parameters of the cylinder are calculated according to the force parameters; the motion parameters of the cylinder are obtained according to the speed parameters of the cylinder and the preset rotation angular velocity, and when it is detected that the motion parameters of the cylinder meet the preset conditions, the motion parameters of the cylinder are output. By setting the combined structure of the control rod and the cylinder, the vortex-induced vibration suppression of the cylinder under the combined action of the rotation and the control rod can be explored, and then a structure that effectively suppresses the vortex-induced vibration can be obtained, which provides a basis for the analysis of the vortex-induced vibration mechanism and response characteristics of the marine riser.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is an overall flow chart of a method for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure provided in an embodiment of the present application;

FIG2 is a schematic diagram of the division effect of a combined vortex-induced vibration numerical model provided in an embodiment of the present application;

FIG3 is a schematic diagram of the division effect of another combined vortex-induced vibration numerical model provided in an embodiment of the present application;

FIG4 is a vorticity contour diagram of a vortex-induced vibration flow field of an appendage-rotating combined cylindrical structure provided in an embodiment of the present application;

FIG5 is a graph showing the relationship between the vortex-induced vibration amplitude and the reduced velocity of an appendage-rotating combined cylindrical structure provided in an embodiment of the present application;

FIG6 is a schematic structural diagram of a vortex-induced vibration calculation device for an appendage-rotating combined cylindrical structure provided in an embodiment of the present application;

FIG. 7 is a schematic structural diagram of another vortex-induced vibration calculation device of an appendage-rotating combined cylindrical structure provided in an embodiment of the present application.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

In the following introduction, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The following introduction provides multiple embodiments of the present application, and different embodiments can be replaced or combined, so the present application can also be considered to include all possible combinations of the same and/or different embodiments recorded. Therefore, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present application should also be considered to include embodiments containing one or more of all other possible combinations of A, B, C, and D, although the embodiment may not be clearly recorded in the following text.

The following description provides examples and does not limit the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements described without departing from the scope of the present application. Various processes or components may be appropriately omitted, substituted or added to each example. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, features described in some examples may be combined in other examples.

Please refer to FIG. 1 , which shows an overall flow chart of a method for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure provided in an embodiment of the present application.

As shown in FIG1 , the vortex-induced vibration calculation method of the appendage-rotating combined cylindrical structure may at least include the following steps:

Step 102: determine the distance between each control rod and the cylinder based on a preset gap ratio and the diameter of the cylinder, and establish a combined vortex-induced vibration numerical model according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods.

In the embodiment of the present application, the structure composed of the marine riser and the control rod is mainly studied. By numerically simulating the fluid-solid coupling between the flow field and the appendage-rotating combined cylindrical structure, the vortex-induced vibration response of the combined structure is studied, and the inhibitory effect of the combined structure on the vortex-induced vibration of the cylinder is analyzed. The vortex-induced vibration calculation method of the appendage-rotating combined cylindrical structure proposed in the present application can be applied to a control terminal installed with ICEM CFD software and Fluent software. The ICEM CFD software can, but is not limited to, generate a combined vortex-induced vibration numerical model composed of a control rod and a cylinder according to the diameter of the cylinder, the preset gap ratio, and the number of control rods input by the user in the control terminal. Here, each control rod in the combined vortex-induced vibration numerical model can be set near the cylinder, and the distance between each control rod and the cylinder is kept consistent, and the combined vortex-induced vibration numerical model can be divided and processed by the ICEM CFD software. Among them, after the ICEM CFD software divides the established combined vortex-induced vibration numerical model, the control terminal can import the file corresponding to the combined vortex-induced vibration numerical model after the division process into the Fluent software, so that the Fluent software can perform subsequent processing on the combined vortex-induced vibration numerical model after the division process. It should be noted that the control terminal can also obtain the UDF secondary development program compiled based on the C language input by the user before the Fluent software runs, and embed the UDF program into the Fluent software through the User Defined Functions window in the Fluent software, so as to ensure that the output result accurately reflects the suppression effect of the combined structure on the cylindrical vortex-induced vibration through the Fluent software embedded with the UDF program. It is understandable that the control terminal can also set the parameters pre-set by the user in the Fluent software during the operation of the Fluent software, so that the Fluent software can achieve more accurate calculations.

Specifically, when calculating the vortex-induced vibration value of the appendage-rotating combined cylindrical structure, the control terminal inputs the preset gap ratio and the diameter of the cylinder input by the user into the ICEM CFD software, so that the ICEM CFD software first calculates the distance between each control rod and the cylinder in the combined vortex-induced vibration numerical model according to the preset gap ratio and the diameter of the cylinder, wherein the preset gap ratio can be understood as the ratio of the distance between the center of each control rod to the center of the cylinder to the diameter of the cylinder, and then the ICEM CFD software can combine the number of control rods, the diameter of the cylinder, and the distance between each control rod and the cylinder to generate a combined vortex-induced vibration numerical model including control rods and cylinders.

As an option of the embodiment of the present application, a combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods, including:

A reference triangle is established based on the center of the cylinder and the diameter of the cylinder; wherein the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder;

Adjust the distance from each vertex of the reference triangle to the center of the inscribed circle according to the distance from each control rod to the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance from each control rod to the cylinder, and use the position of each vertex in the adjusted reference triangle as the relative position between each control rod and the cylinder;

Determining the diameter of each control rod based on the preset diameter ratio and the diameter of the cylinder;

A combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the relative position between each control rod and the cylinder, and the diameter of each control rod.

Specifically, taking the setting of the number of control rods to three as an example, after the ICEM CFD software calculates the distance between each control rod and the cylinder in the combined vortex-induced vibration numerical model according to the preset gap ratio and the diameter of the cylinder, the ICEM CFD software can determine the center of the cylinder based on the diameter of the cylinder, and establish a reference triangle based on the center and diameter of the cylinder. The inscribed circle of the reference triangle is consistent with the cylinder, that is, the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder. It can be understood that the reference triangle here is an equilateral triangle, and there is an intersection point between the inscribed circle and the three sides of the reference triangle, and the line between the intersection point and the center of the inscribed circle is perpendicular to the side corresponding to the intersection point.

Furthermore, after establishing the reference triangle, the ICEM CFD software can adjust the distances between the three vertices of the reference triangle and the center of the inscribed circle according to the calculated distances between each control rod and the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance from each control rod to the cylinder, and the position of each adjusted vertex relative to the center of the inscribed circle can be used as the relative position between each control rod and the cylinder. That is to say, after determining the position of the center of the cylinder, the position of each control rod can be determined according to the relative position between each control rod and the cylinder.

Furthermore, the ICEM CFD software can also calculate the diameter of each control rod based on the input diameter of the cylinder and the preset diameter ratio. The preset diameter ratio can be understood as the ratio between the diameter of the control rod and the diameter of the cylinder. Here, in order to simulate a more realistic state, the diameter of the control rod must be smaller than the diameter of the cylinder, that is, the preset diameter ratio is less than 1.

Furthermore, after determining the relative position between each control rod and the cylinder and the diameter of each control rod, the ICEM CFD software can establish a combined vortex-induced vibration numerical model in combination with the diameter of the cylinder, wherein the combined vortex-induced vibration numerical model can be a rectangular area (the size can be but is not limited to 50D*70D, D is the diameter of the cylinder, and the blockage rate can be but is not limited to being set to 2%), in which a cylinder with the same diameter as the cylinder is arranged (expressed by the diameter of the cylinder), a spring damping system connected to the cylinder, and three control rods respectively arranged near the cylinder (the diameter of each control rod can be but is not limited to 0.25D). Here, the cylinder can simulate lateral movement or longitudinal movement or lateral movement and longitudinal movement during the rotation process. The lateral movement can be understood as the center of the cylinder moving left or right along the axis parallel to the horizontal side of the rectangular area, and the center of the cylinder is set on the axis parallel to the horizontal side of the rectangular area; the longitudinal movement can be understood as the center of the cylinder moving upward or downward along the axis parallel to the vertical side of the rectangular area, and the center of the cylinder is set on the axis parallel to the vertical side of the rectangular area. It should be noted that during the movement of the cylinder, each control rod moves synchronously with the cylinder, the moving speed and displacement of each control rod are consistent with the moving speed and displacement of the cylinder, and each control rod itself does not rotate.

It should be noted that the purpose of setting the control rod in the present application is to cooperate with the forced rotation of the cylinder to further suppress the vortex shedding on the surface of the cylinder to achieve the effect of suppressing vortex-induced vibration.

Step 104 , dividing the combined vortex-induced vibration numerical model, determining the fluid region from the combined vortex-induced vibration numerical model after the division processing, and calculating the flow field characteristics of the fluid region based on preset fluid parameters.

Specifically, after the control terminal establishes the combined vortex-induced vibration numerical model in the ICEM CFD software, the combined vortex-induced vibration numerical model is divided and processed based on the ICEM CFD software to determine the rigid area, the dynamic grid area and the static grid area in the combined vortex-induced vibration numerical model.

As another option of the embodiment of the present application, the combined vortex-induced vibration numerical model is divided and processed, including:

In the combined vortex-induced vibration numerical model, the center of the cylinder and the center of each control rod are determined respectively;

Divide a region whose distance from the center of the cylinder is within a preset first distance interval as a first rigid region;

Dividing a region whose distance from the center of each control rod is within a preset second distance interval as a second rigid region;

Divide the area whose distance from the center of the cylinder is within a preset third distance interval as a dynamic grid area;

The area of the combined vortex-induced vibration numerical model excluding the first rigid area, the second rigid area and the dynamic grid area is divided into a static grid area.

Specifically, after establishing the combined vortex-induced vibration numerical model, the ICEM CFD software can determine the center of the cylinder and the center of each control rod in the combined vortex-induced vibration numerical model, and divide the area whose distance from the center of the cylinder is in a preset first distance interval into a first rigid area, and the first rigid area can be, but is not limited to, represented by [D, L1], where D is the diameter of the cylinder. Then, the area whose distance from the center of each control rod is in a preset second distance interval can be divided into a second rigid area, and the second rigid area can be, but is not limited to, represented by [0.25D, L2], where 0.25D is the diameter of the control rod, and the second rigid area does not overlap with the first rigid area.

Then, the ICEM CFD software may divide the area whose distance from the center of the cylinder is in a preset third distance interval into a moving mesh area, which may be but is not limited to being represented as [L1, L3], wherein the cylinder and each control rod may move within the moving mesh area.

Then, the ICEM CFD software can divide the area of the combined vortex-induced vibration numerical model except the first rigid area, the second rigid area and the dynamic mesh area into a static mesh area.

It can be understood that after the combined vortex-induced vibration numerical model is divided into regions, in order to realize the dynamic mesh model, the combined vortex-induced vibration numerical model after the region division can also be meshed. The mesh type can be but is not limited to a triangular mesh, and the file corresponding to the combined vortex-induced vibration numerical model after the mesh division can be imported into the Fluent software by the control terminal.

Here, please refer to the schematic diagram of the division effect of a combined vortex-induced vibration numerical model provided by an embodiment of the present application shown in Figure 2. As shown in Figure 2, the combined vortex-induced vibration numerical model includes a cylinder and three control rods, wherein the boundary layer part of the cylinder is divided into a first rigid area (see the enlarged view), the boundary layer part of the control rod is divided into a second rigid area (see the enlarged view), the vicinity of the cylinder is divided into a dynamic mesh area, and all other areas are divided into static mesh areas, and each area is divided into multiple triangular meshes.

Furthermore, after the control terminal imports the combined vortex-induced vibration numerical model after the division process from the ICEM CFD software into the Fluent software, all other regions except the first rigid region and the second rigid region in the combined vortex-induced vibration numerical model derived from the Fluent software can be used as the initial fluid region, and the initial fluid region can be trimmed in combination with the boundary conditions pre-set in the Fluent software to obtain the target fluid region. Among them, the boundary conditions can include but are not limited to the left boundary condition, the right boundary condition, and the upper and lower side boundaries, the left boundary condition is the velocity inlet (velocity-inlet), the right boundary condition is the pressure outlet (pressure-out), and the upper and lower side boundaries are symmetry boundaries (symmetry).

Here, you can also refer to the schematic diagram of the division effect of another combined vortex-induced vibration numerical model provided by the embodiment of the present application shown in Figure 3. As shown in Figure 3, the combined vortex-induced vibration numerical model includes a cylinder, three control rods, a spring damping system connected to the cylinder in a transverse arrangement, and a spring damping system connected to the cylinder in a vertical arrangement. The left side of the combined vortex-induced vibration numerical model corresponds to the velocity inlet, the right side of the combined vortex-induced vibration numerical model corresponds to the pressure outlet, and the upper and lower sides of the combined vortex-induced vibration numerical model correspond to symmetric boundaries, and the distance from the symmetric boundary to the center of the cylinder remains consistent (the diagram is 25D, and D is the diameter of the cylinder). In Figure 3, the distance between the velocity inlet side and the center of the cylinder is 20D, and the distance between the pressure outlet side and the center of the cylinder is 50D.

Further, after obtaining the target fluid region, the control terminal can use Fluent software, combined with the target fluid region and preset fluid parameters, to calculate the flow field characteristics of the fluid region. Among them, the preset fluid parameters can be, but are not limited to, pre-input into the Fluent software by the user, and the preset fluid parameters can specifically include the density and kinematic viscosity of the fluid. The fluid object simulated here can generally be set to water. It can be understood that in the process of calculating the flow field characteristics of the fluid region based on the Fluent software, the flow field of the target fluid region can be discretized into a finite number of nodes based on the finite volume method by the Fluent software, and then the Reynolds average N-S equation corresponding to the fluid can be solved by the RANS method to obtain the corresponding flow field characteristics, and the flow field characteristics can be, but are not limited to, including the velocity, pressure and other information of the fluid in the entire flow field. It should be noted that the use of Fluent software to calculate the flow field characteristics of the fluid region in the embodiment of the present application can be a common technical means in the art, and no further description is given here.

Of course, before calculating the flow field characteristics of the fluid region based on the Fluent software, the control terminal can also input the preset solution parameters for calculating the flow field characteristics into the Fluent software, so that the Fluent software can combine the target fluid region, the preset fluid parameters and the solution parameters to quickly and accurately calculate the flow field characteristics of the fluid region. Among them, the solution parameters can include but are not limited to solution algorithms, discrete formats and solution accuracy.

It is also understood that before calculating the flow field characteristics of the fluid region, the control terminal can also control the Fluent software to initialize the target fluid region in combination with the preset fluid parameters and the target fluid region to ensure the reliability of the simulated target fluid region. The initialization operation can be, but is not limited to, the control terminal operating the Fluent software according to the automatic control program, which is not limited to this.

Step 106: Determine the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculate the velocity parameters of the cylinder according to the force parameters.

Specifically, after calculating the flow field characteristics of the fluid area, the control terminal can use the UDF program embedded in the Fluent software to call the macro Compute_Force_And_Moment to extract the surface pressure load of the cylinder (that is, it can be understood as the pressure distribution data applied by the fluid on the surface of the cylinder) from the flow field characteristics of the fluid area. Then, the surface pressure load of the cylinder can be divided into the pressure load in the downstream direction (also understood as the vertical flow direction) and the pressure load in the transverse direction according to different flow directions, and the pressure load in the downstream direction and the pressure load in the transverse direction can be superimposed and calculated respectively, so as to obtain the fluid force of the cylinder in the downstream direction and the fluid force in the transverse direction in the fluid area respectively.

It can be understood that according to the combined vortex-induced vibration numerical model shown in Figure 3, it can be seen that the cylinder is provided with spring damping systems in the horizontal and vertical directions respectively, and the movement direction of the cylinder is mainly horizontal left-right movement and vertical up-and-down movement. Based on this, the fluid force of the cylinder in the downstream direction and the fluid force in the transverse direction in the fluid area are obtained, which facilitates the subsequent accurate calculation of the movement state of the cylinder in the fluid area.

Here, in an embodiment of the present application, the UDF program embedded in the Fluent software may also include, but is not limited to, pre-set cylinder dynamic parameters, such as the diameter, density, natural frequency, damping coefficient and other parameters of the cylinder, so as to effectively ensure the accuracy and applicability of the model simulation.

Furthermore, after obtaining the fluid force of the cylinder in the downstream direction and the fluid force in the cross-flow direction in the fluid region, the control terminal can also use the UDF program embedded in the Fluent software to substitute the fluid force of the cylinder in the downstream direction and the fluid force of the cylinder in the cross-flow direction in the fluid region into the preset dynamic equation, and based on the preset solution parameters and the preset cylinder dynamic parameters, perform discrete calculations on the dynamic equation to obtain the velocity parameters of the cylinder. The preset dynamic equation can be, but is not limited to, expressed as follows:

In the above mentioned kinetic equation, It can be understood as the mass ratio of the cylinder, It can be corresponded to the density of the fluid, m can be corresponded to the mass of the cylinder, and D can be corresponded to the diameter parameter of the cylinder. It can be understood as the downstream force coefficient on the cylindrical surface. It can be corresponded to the fluid force of the cylinder in the downstream direction in the fluid area, It can be understood as the cross-flow coefficient of the cylindrical surface. It can be corresponded to the fluid force of the cylinder in the cross-flow direction in the fluid area, and U can be corresponded to the inlet velocity of the flow field. , as well as They can correspond to the dimensionless displacement, velocity and acceleration of the cylinder in the cross-flow direction, , as well as They can correspond to the dimensionless displacement, velocity and acceleration of the cylinder in the downstream direction. Since the cylinder is supported by a spring-damper system, including linear elastic springs (transverse direction) and (downstream direction), c can correspond to the damping coefficient of the system. It can be understood as the reduced speed, It can be corresponded to the natural frequency of the cylinder.

Furthermore, the control terminal can utilize the UDF program embedded in the Fluent software to call the iterative program based on the fourth-order Runge-Kutta method and the preset solution parameters to discretely solve the above-mentioned dynamic equations to obtain the velocity parameters of the cylinder. The preset solution parameters may include but are not limited to turbulence model, solution algorithm, discrete format, solution accuracy and time step. The velocity parameters of the cylinder may include but are not limited to displacement, velocity and acceleration. The specific solution process is as follows:

in:

In the above formula, It can be corresponded to the calculation time step, It can be understood as the natural circular frequency. It can be understood as the damping ratio.

Step 108: Obtain motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotational angular velocity, and output the motion parameters of the cylinder when it is detected that the motion parameters of the cylinder meet preset conditions.

Specifically, after calculating the velocity parameters (displacement, velocity and acceleration) of the cylinder, the control terminal can use the UDF program embedded in the Fluent software to call the macro DEFINE_CG_MOTION to pass the velocity of the cylinder to the combined vortex-induced vibration numerical model in the Fluent software, and assign the preset angular velocity of rotation in the combined vortex-induced vibration numerical model through the macro DEFINE_CG_MOTION, so that the cylinder in the combined vortex-induced vibration numerical model can simulate the movement according to the velocity and angular velocity of rotation, and each control rod can move synchronously with the cylinder at the same speed.

Among them, the control terminal can calculate the motion parameters of the cylinder corresponding to each interval moment in sequence according to the preset interval moments, wherein the motion parameters of the cylinder may include parameters such as lift coefficient, drag coefficient, transverse amplitude and downstream amplitude.

It is understandable that the control terminal can also pre-select the specific type of the motion parameter of the cylinder in the Fluent software, so that the Fluent software can calculate the corresponding type of results in combination with the motion of the cylinder in the numerical model of flow around the cylinder. For example, the control terminal can pre-set the extraction of lift coefficient ( ）、Drag coefficient（ ), transverse amplitude ( ) and the downstream amplitude ( ) and other calculation data.

Furthermore, after obtaining the motion parameters of the cylinder corresponding to each interval moment, the control terminal can draw an amplitude curve according to the amplitude parameters in the motion parameters of the cylinder corresponding to each interval moment, and determine whether there is a curve showing periodic changes in the amplitude curve. Among them, the curve showing periodic changes can generally be a sine wave or a cosine wave with consistent amplitude and period. It is possible that when it is detected that there is a curve showing periodic changes in the amplitude curve, it indicates that the motion state of the cylinder has stabilized, and then it can be determined that the motion parameters of the cylinder meet the preset conditions, and the corresponding motion parameters of the cylinder are output.

Of course, in the embodiment of the present application, it is also possible but not limited to determine whether the motion parameters of the cylinder meet the preset conditions by judging whether all the amplitudes in the amplitude curve are within the preset amplitude range, which is not limited to this.

It can be understood that when it is detected that there is no curve showing periodic changes in the amplitude curve, it is characterized that there are still large fluctuations in the cylinder, and it is determined that the motion parameters of the cylinder do not meet the preset conditions. In this case, the cylinder and each control rod can be controlled to move in combination with the motion parameters of the cylinder at the current moment, and the corresponding fluid area can be updated after the movement of the cylinder and each control rod.

Next, after obtaining the fluid region after the update processing, the control terminal can, but is not limited to, calculate the motion parameters of the cylinder at the next moment in combination with the above-mentioned steps, and loop until the motion parameters of the cylinder meet the preset conditions.

In the embodiment of the present application, the flow field calculation is carried out by discretizing the Reynolds-averaged incompressible Navier-Stokes equations through the finite volume method, and the structural analysis is carried out by discretizing the structural dynamics equations through the fourth-order Runge-Kutta method; then, the grid is established by adopting the idea of "rigid follower area + dynamic grid area + static grid area", and the fluid-solid coupling calculation is realized through the cyclic interactive iterative solution between the fluid domain in Fluent and the solid domain in the UDF program, which can accurately reflect the vortex-induced vibration response of the combined structure and provide a basis for the analysis of the vortex-induced vibration mechanism and response characteristics of the marine riser.

It can also be understood that after the cylinder in the combined vortex-induced vibration numerical model is simulated to move according to the speed and the rotational angular velocity, the control terminal can, but is not limited to, export the corresponding case file and data file through Fluent software, and use post-processing software such as Tecplot to analyze and draw the vorticity cloud map and the velocity cloud map. Reference can be made here to the vorticity contour map of the vortex-induced vibration flow field of the vortex-induced vibration combined cylindrical structure provided in an embodiment of the present application, which is shown in FIG.

As shown in Figure 4, the vortex-induced vibration flow field vorticity contour diagrams corresponding to the appendage-rotating combined cylindrical structure when the speed ratio is 0, 0.2, 0.4, 0.6, 0.8 and 1, respectively, where the speed ratio can be understood as the ratio between 2 times the flow field velocity and the product of the diameter of the cylinder and the preset rotational angular velocity. It can be seen that for the case where the cylinder does not rotate (the speed ratio is 0), although the control rod affects the flow field around the cylinder, there is still vortex shedding on the surface of the cylinder, the amplitude of the cylinder is not significantly suppressed, and the flow field width (cross-flow direction) is large. However, by increasing the speed ratio of the cylinder, the vortex shedding on the surface of the cylinder is suppressed when the speed ratio is 0.6, and the corresponding cylinder amplitude is also significantly reduced, which is manifested as a reduction in the flow field width (cross-flow direction), that is, the effective suppression of vortex-induced vibration is achieved.

It can also be understood that after the cylinder in the combined vortex-induced vibration numerical model is simulated to move according to the speed and the rotational angular velocity, the control terminal can, but is not limited to, export the corresponding case file and data file through the Fluent software, and use post-processing software such as Origin to analyze and draw the amplitude and fluid force coefficient trend graph. Here, please refer to the relationship diagram between the vortex-induced vibration amplitude and the reduced speed of a body-rotating combined cylindrical structure provided in an embodiment of the present application shown in FIG5.

As shown in Figure 5, the upper part is a trend diagram of the relationship between the cross-flow amplitude and the reduced velocity of the appendage-rotating combined cylindrical structure. The horizontal axis in the figure corresponds to the reduced velocity mentioned above. , the ordinate can correspond to the cross-flow amplitude , and each curve in the figure corresponds to a speed ratio. It can be seen that when the cylinder speed increases to a certain extent, the vibration of the cylinder will be strengthened. For example, when the speed ratio is equal to 2, the vibration amplitude is larger. Based on this, it can be determined that the speed ratio of the cylinder needs to be controlled in the range of 0-1. The lower part is a trend diagram of the downstream amplitude and reduced speed relationship of the appendage-rotating combined cylinder structure. The horizontal axis in the figure can correspond to the reduced speed mentioned above. , the ordinate can correspond to the downstream amplitude , and each curve in the figure corresponds to a speed ratio. It can be seen that the rotation of the cylinder will significantly enhance the downstream amplitude of the cylinder (for non-rotating cylindrical vortex-induced vibration, the downstream amplitude is one order of magnitude smaller than the transverse amplitude), and the difference between the transverse amplitude and the downstream amplitude is not large. Based on this, combined with the trend graph of the transverse amplitude and the reduced velocity relationship of the appendage-rotating combined cylindrical structure and the trend graph of the downstream amplitude and the reduced velocity relationship, it can be concluded that the amplitude values of the two directions of the appendage-rotating combined cylindrical structure are very similar.

Please refer to FIG. 6 , which shows a schematic structural diagram of a vortex-induced vibration calculation device of an appendage-rotating combined cylindrical structure provided in an embodiment of the present application.

As shown in FIG6 , the vortex-induced vibration calculation device of the appendage-rotating combined cylindrical structure may at least include a model building module 601, a first calculation module 602, a second calculation module 603 and a parameter output module 604, wherein:

A model building module 601 is used to determine the distance between each control rod and the cylinder based on a preset gap ratio and the diameter of the cylinder, and to establish a combined vortex-induced vibration numerical model according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; wherein the ratio of the distance between each control rod and the cylinder to the diameter of the cylinder is the preset gap ratio;

The first calculation module 602 is used to divide the combined vortex-induced vibration numerical model, determine the fluid region from the combined vortex-induced vibration numerical model after the division process, and calculate the flow field characteristics of the fluid region based on the preset fluid parameters;

The second calculation module 603 is used to determine the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculate the velocity parameters of the cylinder according to the force parameters;

The parameter output module 604 is used to obtain the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotation angular velocity, and output the motion parameters of the cylinder when it is detected that the motion parameters of the cylinder meet the preset conditions.

In some possible embodiments, the at least two control rods are specifically three control rods;

The model building module includes:

A reference triangle is established based on the center of the cylinder and the diameter of the cylinder; wherein the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder;

Adjust the distance from each vertex of the reference triangle to the center of the inscribed circle according to the distance from each control rod to the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance from each control rod to the cylinder, and use the position of each vertex in the adjusted reference triangle as the relative position between each control rod and the cylinder;

Determining the diameter of each control rod based on the preset diameter ratio and the diameter of the cylinder;

A combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the relative position between each control rod and the cylinder, and the diameter of each control rod.

In some possible embodiments, the first calculation module includes:

In the combined vortex-induced vibration numerical model, the center of the cylinder and the center of each control rod are determined respectively;

Divide a region whose distance from the center of the cylinder is within a preset first distance interval as a first rigid region;

Dividing a region whose distance from the center of each control rod is within a preset second distance interval as a second rigid region;

Divide the area whose distance from the center of the cylinder is within a preset third distance interval as a dynamic grid area;

The area of the combined vortex-induced vibration numerical model excluding the first rigid area, the second rigid area and the dynamic grid area is divided into a static grid area.

In some possible embodiments, the first calculation module further includes:

All regions except the first rigid region and the second rigid region in the combined vortex-induced vibration numerical model after the division process are used as the initial fluid region;

Based on the preset boundary conditions, the initial fluid region is clipped to obtain the target fluid region;

According to the target fluid region and preset fluid parameters, the flow field characteristics of the fluid region are calculated.

In some possible embodiments, the second calculation module includes:

The surface pressure load of the cylinder is extracted from the flow field characteristics of the fluid region;

The pressure load in the downstream direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the downstream direction in the fluid area;

The pressure load in the cross-flow direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the cross-flow direction in the fluid area;

Substitute the fluid force of the cylinder in the fluid region in the downstream direction and the fluid force of the cylinder in the fluid region in the cross-stream direction into the preset dynamic equation;

The dynamic equations are discretely calculated based on the preset solution parameters to obtain the velocity parameters of the cylinder.

In some possible embodiments, the parameter output module includes:

Draw an amplitude curve based on the motion parameters of the cylinder, and determine whether there is a curve showing periodic changes in the amplitude curve;

When it is detected that there is a curve showing periodic changes in the amplitude curve, it is determined that the motion parameters of the cylinder meet the preset conditions, and the motion parameters of the cylinder are output.

In some possible embodiments, the device further includes:

After obtaining the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotational angular velocity, when it is detected that the motion parameters of the cylinder do not meet the preset conditions, the cylinder and each control rod are controlled to move based on the motion parameters of the cylinder, and the fluid area is updated;

Based on the preset fluid parameters, the flow field characteristics of the updated fluid region are calculated, and the motion parameters of the cylinder are recalculated according to the flow field characteristics of the updated fluid region.

Those skilled in the art can clearly understand that the technical solutions of the embodiments of the present application can be implemented with the help of software and/or hardware. The "unit" and "module" in this specification refer to software and/or hardware that can independently complete or cooperate with other components to complete specific functions, where the hardware can be, for example, a field programmable gate array (FPGA), an integrated circuit (IC), etc.

Please refer to FIG. 7 , which shows a schematic structural diagram of a vortex-induced vibration calculation device of another appendage-rotating combined cylindrical structure provided in an embodiment of the present application.

As shown in FIG. 7 , the vortex-induced vibration calculation device 700 of the appendage-rotating combined cylindrical structure may include at least one processor 701 , at least one network interface 704 , a user interface 703 , a memory 705 and at least one communication bus 702 .

The communication bus 702 may be used to realize the connection and communication among the above-mentioned components.

The user interface 703 may include buttons, and the optional user interface may also include a standard wired interface or a wireless interface.

The network interface 704 may include, but is not limited to, a Bluetooth module, an NFC module, a Wi-Fi module, etc.

Among them, the processor 701 may include one or more processing cores. The processor 701 uses various interfaces and lines to connect the various parts of the vortex-induced vibration calculation device 700 of the attached-rotating combined cylindrical structure, and executes various functions and processes data of the vortex-induced vibration calculation device 700 of the routing attached-rotating combined cylindrical structure by running or executing instructions, programs, code sets or instruction sets stored in the memory 705, and calling data stored in the memory 705. Optionally, the processor 701 can be implemented in at least one hardware form of DSP, FPGA, and PLA. The processor 701 can integrate one or a combination of CPU, GPU, modem, etc. Among them, the CPU mainly processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to process wireless communications. It can be understood that the above-mentioned modem may not be integrated into the processor 701, and it can be implemented by a single chip.

Among them, the memory 705 may include RAM or ROM. Optionally, the memory 705 includes a non-transient computer-readable medium. The memory 705 can be used to store instructions, programs, codes, code sets or instruction sets. The memory 705 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 705 may also be at least one storage device located away from the aforementioned processor 701. As shown in Figure 7, the memory 705 as a computer storage medium may include an operating system, a network communication module, a user interface module, and a vortex-induced vibration calculation application for an appendage-rotating combined cylindrical structure.

Specifically, the processor 701 may be used to call the vortex-induced vibration calculation application program of the appendage-rotating combined cylindrical structure stored in the memory 705, and specifically perform the following operations:

The distance between each control rod and the cylinder is determined based on a preset gap ratio and the diameter of the cylinder, and a combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; wherein the ratio of the distance between each control rod and the cylinder to the diameter of the cylinder is the preset gap ratio;

The combined vortex-induced vibration numerical model is divided, a fluid region is determined from the combined vortex-induced vibration numerical model after the division process, and a flow field characteristic of the fluid region is calculated based on preset fluid parameters;

Determine the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculate the velocity parameters of the cylinder based on the force parameters;

The motion parameters of the cylinder are obtained according to the speed parameters of the cylinder and the preset rotation angular velocity, and when it is detected that the motion parameters of the cylinder meet the preset conditions, the motion parameters of the cylinder are output.

In some possible embodiments, the at least two control rods are specifically three control rods;

According to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods, a combined vortex-induced vibration numerical model is established, including:

A reference triangle is established based on the center of the cylinder and the diameter of the cylinder; wherein the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder;

Adjust the distance from each vertex of the reference triangle to the center of the inscribed circle according to the distance from each control rod to the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance from each control rod to the cylinder, and use the position of each vertex in the adjusted reference triangle as the relative position between each control rod and the cylinder;

Determining the diameter of each control rod based on the preset diameter ratio and the diameter of the cylinder;

A combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the relative position between each control rod and the cylinder, and the diameter of each control rod.

In some possible embodiments, the combined vortex-induced vibration numerical model is divided and processed, including:

In the combined vortex-induced vibration numerical model, the center of the cylinder and the center of each control rod are determined respectively;

Divide a region whose distance from the center of the cylinder is within a preset first distance interval as a first rigid region;

Dividing a region whose distance from the center of each control rod is within a preset second distance interval as a second rigid region;

Divide the area whose distance from the center of the cylinder is within a preset third distance interval as a dynamic grid area;

The area of the combined vortex-induced vibration numerical model excluding the first rigid area, the second rigid area and the dynamic grid area is divided into a static grid area.

In some possible embodiments, a fluid region is determined from the combined vortex-induced vibration numerical model after the division process, and a flow field characteristic of the fluid region is calculated based on preset fluid parameters, including:

All regions except the first rigid region and the second rigid region in the combined vortex-induced vibration numerical model after the division process are used as the initial fluid region;

Based on the preset boundary conditions, the initial fluid region is clipped to obtain the target fluid region;

According to the target fluid region and preset fluid parameters, the flow field characteristics of the fluid region are calculated.

In some possible embodiments, determining the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculating the velocity parameters of the cylinder according to the force parameters include:

The surface pressure load of the cylinder is extracted from the flow field characteristics of the fluid region;

The pressure load in the downstream direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the downstream direction in the fluid area;

The pressure load in the cross-flow direction of the surface pressure load of the cylinder is superimposed and calculated to obtain the fluid force of the cylinder in the cross-flow direction in the fluid area;

Substitute the fluid force of the cylinder in the fluid region in the downstream direction and the fluid force of the cylinder in the fluid region in the cross-stream direction into the preset dynamic equation;

The dynamic equations are discretely calculated based on the preset solution parameters to obtain the velocity parameters of the cylinder.

In some possible embodiments, when it is detected that the motion parameters of the cylinder meet a preset condition, the motion parameters of the cylinder are output, including:

Draw an amplitude curve based on the motion parameters of the cylinder, and determine whether there is a curve showing periodic changes in the amplitude curve;

When it is detected that there is a curve showing periodic changes in the amplitude curve, it is determined that the motion parameters of the cylinder meet the preset conditions, and the motion parameters of the cylinder are output.

In some possible embodiments, after obtaining the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotation angular velocity, the method further includes:

When it is detected that the motion parameters of the cylinder do not meet the preset conditions, the cylinder and each control rod are controlled to move based on the motion parameters of the cylinder, and the fluid area is updated;

Based on the preset fluid parameters, the flow field characteristics of the updated fluid region are calculated, and the motion parameters of the cylinder are recalculated according to the flow field characteristics of the updated fluid region.

The present application also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of the above method are implemented. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and/or data.

It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program codes.

A person skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by entering a program to instruct related hardware. The program can be stored in a computer-readable memory, and the memory can include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

The above are only exemplary embodiments of the present disclosure and cannot be used to limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field that are not recorded in the present disclosure. The description and examples are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

Claims (10)

1. A method for calculating vortex-induced vibration of an appendage-rotating combined cylindrical structure, characterized by comprising: The distance between each control rod and the cylinder is determined based on a preset gap ratio and the diameter of the cylinder, and a combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; wherein the preset gap ratio is the ratio of the distance between each control rod and the cylinder to the diameter of the cylinder; Performing a division process on the combined vortex-induced vibration numerical model, determining a fluid region from the combined vortex-induced vibration numerical model after the division process, and calculating a flow field characteristic of the fluid region based on preset fluid parameters; Determining force parameters of the cylinder in the fluid region based on flow field characteristics of the fluid region, and calculating velocity parameters of the cylinder according to the force parameters; The motion parameters of the cylinder are obtained according to the speed parameters of the cylinder and the preset rotational angular velocity, and when it is detected that the motion parameters of the cylinder meet the preset conditions, the motion parameters of the cylinder are output. 2. The method according to claim 1, characterized in that the at least two control rods are specifically three control rods; The method of establishing a combined vortex-induced vibration numerical model according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods comprises: A reference triangle is established based on the center of the cylinder and the diameter of the cylinder; wherein the diameter of the inscribed circle of the reference triangle is the same as the diameter of the cylinder, and the center of the inscribed circle of the reference triangle is the same as the center of the cylinder; Adjust the distance from each vertex of the reference triangle to the center of the inscribed circle according to the distance between each control rod and the cylinder, so that the distance from each vertex to the center of the inscribed circle is the same as the distance between each control rod and the cylinder, and use the position of each vertex in the reference triangle after adjustment as the relative position between each control rod and the cylinder; Determining the diameter of each of the control rods based on a preset diameter ratio and the diameter of the cylinder; A combined vortex-induced vibration numerical model is established according to the diameter of the cylinder, the relative position between each of the control rods and the cylinder, and the diameter of each of the control rods. 3. The method according to claim 1, characterized in that the division process of the combined vortex-induced vibration numerical model comprises: In the combined vortex-induced vibration numerical model, the center of the cylinder and the center of each control rod are respectively determined; Dividing a region whose distance from the center of the cylinder is within a preset first distance interval as a first rigid region; Dividing a region whose distance from the center of each control rod is within a preset second distance interval as a second rigid region; Dividing an area whose distance from the center of the cylinder is within a preset third distance interval as a dynamic grid area; The area of the combined vortex-induced vibration numerical model excluding the first rigid area, the second rigid area and the dynamic grid area is divided into a static grid area. 4. The method according to claim 3, characterized in that the step of determining a fluid region from the combined vortex-induced vibration numerical model after the division process and calculating the flow field characteristics of the fluid region based on preset fluid parameters comprises: taking all regions of the combined vortex-induced vibration numerical model after the division process except the first rigid region and the second rigid region as the initial fluid region; Based on the preset boundary conditions, the initial fluid region is clipped to obtain a target fluid region; The flow field characteristics of the fluid region are calculated according to the target fluid region and preset fluid parameters. 5. The method according to claim 1, characterized in that the step of determining the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculating the velocity parameters of the cylinder according to the force parameters, comprises: extracting the surface pressure load of the cylinder from the flow field characteristics of the fluid region; Superimposing and calculating the pressure load in the downstream direction of the surface pressure load of the cylinder, to obtain the fluid force of the cylinder in the downstream direction in the fluid region; Superimposing and calculating the pressure load in the transverse flow direction among the surface pressure loads of the cylinder, to obtain the fluid force of the cylinder in the transverse flow direction in the fluid region; Substituting the fluid force of the cylinder in the fluid region in the downstream direction and the fluid force of the cylinder in the fluid region in the cross-stream direction into a preset dynamic equation; The dynamic equation is discretely calculated based on preset solution parameters to obtain the velocity parameters of the cylinder. 6. The method according to claim 1, characterized in that when the motion parameter of the cylinder is detected to meet a preset condition, outputting the motion parameter of the cylinder comprises: Drawing an amplitude curve based on the motion parameters of the cylinder, and determining whether there is a curve showing periodic changes in the amplitude curve; When it is detected that there is a curve showing periodic changes in the amplitude curve, it is determined that the motion parameters of the cylinder meet a preset condition, and the motion parameters of the cylinder are output. 7. The method according to claim 1, characterized in that after obtaining the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotation angular velocity, it further comprises: When it is detected that the motion parameter of the cylinder does not meet the preset condition, the cylinder and each of the control rods are controlled to move based on the motion parameter of the cylinder, and the fluid region is updated; Based on the preset fluid parameters, the flow field characteristics of the fluid region after the update processing are calculated, and the motion parameters of the cylinder are recalculated according to the flow field characteristics of the fluid region after the update processing. 8. A vortex-induced vibration calculation device for an appendage-rotating combined cylindrical structure, characterized by comprising: A model building module, used to determine the distance between each control rod and the cylinder based on a preset gap ratio and the diameter of the cylinder, and to establish a combined vortex-induced vibration numerical model according to the diameter of the cylinder, the distance between each control rod and the cylinder, and at least two control rods; wherein the preset gap ratio is the ratio of the distance between each control rod and the cylinder to the diameter of the cylinder; A first calculation module is used to divide the combined vortex-induced vibration numerical model, determine the fluid region from the combined vortex-induced vibration numerical model after the division process, and calculate the flow field characteristics of the fluid region based on preset fluid parameters; A second calculation module is used to determine the force parameters of the cylinder in the fluid region based on the flow field characteristics of the fluid region, and calculate the velocity parameters of the cylinder according to the force parameters; The parameter output module is used to obtain the motion parameters of the cylinder according to the speed parameters of the cylinder and the preset rotation angular velocity, and output the motion parameters of the cylinder when it is detected that the motion parameters of the cylinder meet the preset conditions. 9. A vortex-induced vibration calculation device for an appendage-rotating combined cylindrical structure, characterized in that it includes a processor and a memory; The processor is connected to the memory; The memory is used to store executable program code; The processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to execute the steps of the method according to any one of claims 1 to 7. 10. A computer-readable storage medium having a computer program stored thereon, characterized in that the computer-readable storage medium stores instructions, and when the instructions are executed on a computer or a processor, the computer or the processor executes the steps of the method according to any one of claims 1 to 7.