CN107826235A - Culvert type thrust turbofan - Google Patents

Abstract

The invention discloses a ducted thrust turbofan, relates to the technical field of aircraft, and aims to solve the technical problems of low mechanical efficiency and high working noise of the existing thrust propeller. The ducted thrust turbofan described in the present invention comprises sequentially from the inside to the outside: a blade hub, a turbofan blade and a duct casing, and the turbofan blades include a plurality; The outer side wall is seamlessly connected, the outer side is seamlessly connected with the inner side wall of the duct casing, and each turbofan blade extends spirally from one end to the other end along the axial direction of the blade hub.

Description

ducted thrust turbofan

technical field

The invention relates to the technical field of aircraft, in particular to a ducted thrust turbofan.

Background technique

A thrust propeller is a type of aircraft engine. A propeller is a device that converts the rotational power of the engine into propulsion power by rotating the blades in the air or water. There can be 2 or 3 blades connected to the hub. There are many types of propellers, and they are widely used, such as propellers for aircraft and ships.

At present, the thrust propellers in the prior art mainly include: a rotating shaft connected to the hub, the hub is equipped with blades, and the rotating shaft is connected to a power device, so that the power device can drive the rotating shaft to rotate , and then drive the propeller hub and the propeller blades to rotate circumferentially around the rotating shaft.

The inventors of the present application have realized that the existing thrust propellers have fewer blades, and the propellers must maintain a higher rotational speed to produce the required thrust, so the ends of the blades are prone to eddy currents and shock waves, so the blades Large vibration, high working noise and low mechanical efficiency.

Contents of the invention

The purpose of the present invention is to provide a ducted thrust turbofan to solve the technical problems of low mechanical efficiency and high working noise of the existing thrust propellers.

The present invention provides a ducted thrust turbofan, which includes: a blade hub, a turbofan blade, and a ducted casing from the inside to the outside, and the turbofan blades include a plurality; the inner side of each turbofan blade The outer side wall of the blade hub is seamlessly connected, the outer side is seamlessly connected with the inner side wall of the duct casing, and each of the turbofan blades spirally extends from one end to the other end along the axial direction of the blade hub .

In the ducted thrust turbofan provided by the present invention, the center of the blade hub is provided with a shaft-through hole in the axial direction, and the shaft-through hole is used for connecting a driving device.

In the ducted thrust turbofan provided by the present invention, one end of each of the turbofan blades is seamlessly fixed on the blade hub, and the normal line of the starting surface is facing the axis of the blade hub, and 40 The angle of attack of °-45° extends downward in a spiral manner, and the other end of the formed turbofan surface is seamlessly fixed on the duct shell.

In the ducted thrust turbofan provided by the present invention, the angle of attack is 45°.

In the ducted thrust turbofan provided by the present invention, the turbofan blades include 10-20 pieces.

In the ducted thrust turbofan provided by the present invention, the turbofan blades include 10 pieces.

In the ducted thrust turbofan provided by the present invention, the ratio of the axial length of the blade hub to the diameter of the ducted shell is 1:1-3:1.

In the ducted thrust turbofan provided by the present invention, the ratio of the axial length of the blade hub to the diameter of the ducted casing is 1:1.

In the ducted thrust turbofan provided by the present invention, an outer fairing is also provided on the outer side of the ducted casing.

Compared with the prior art, the ducted thrust turbofan of the present invention has the following advantages:

In the ducted thrust turbofan provided by the present invention, it includes: a blade hub, a turbofan blade and a ducted casing from the inside to the outside, and the turbofan blades include a plurality; the inner side of each turbofan blade is connected to the blade hub The outer side wall is seamlessly connected, the outer side is seamlessly connected with the inner side wall of the duct casing, and each turbofan blade extends spirally from one end to the other end along the axial direction of the blade hub. From this analysis, it can be seen that in the ducted thrust turbofan provided by the present invention, since the inner side of each turbofan blade is seamlessly connected with the outer sidewall of the blade hub, and the outer side is seamlessly connected with the inner sidewall of the ducted casing, and each The turbofan blades spirally extend from one end to the other end along the axial direction of the blade hub, so a completely closed spiral cavity can be formed, so that there is no additional resistance when the air rotates at high speed in it, and the air working medium is under strong centrifugal force. Under the action, there will be no spillage, and the end of the turbofan blades will not be able to generate eddy currents or shock waves, which can effectively improve mechanical efficiency and reduce working noise.

In addition, in the ducted thrust turbofan provided by the present invention, since the inner side of each turbofan blade is seamlessly connected with the outer sidewall of the blade hub, and the outer side is seamlessly connected with the inner sidewall of the ducted casing, and each turbofan blade One end along the axial direction of the blade hub spirally extends to the other end, so the overall structural strength of the ducted thrust turbofan is extremely strong, so that the blade hub, turbofan blades and duct casing can be reduced in weight as much as possible, for example, using High-strength composite materials or one-time molding using 3D printing technology.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the specific embodiments or the prior art. Apparently, the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other forms of design drawings based on these drawings without creative work.

Fig. 1 is a schematic diagram of the internal structure of a ducted thrust turbofan provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of the overall structure of the ducted thrust turbofan provided by the embodiment of the present invention.

In the figure: 1 - turbofan blade; 2 - shaft hole; 3 - blade hub; 4 - duct casing; 5 - spiral cavity; 6 - air inlet; 7 - air jet.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "inner" and "outer" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplified descriptions, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the invention.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; may be mechanically connected, may be directly connected. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

Fig. 1 is a schematic diagram of the internal structure of the ducted thrust turbofan provided by the embodiment of the present invention; Fig. 2 is a schematic diagram of the overall structure of the ducted thrust turbofan provided by the embodiment of the present invention.

As shown in Figures 1 and 2, an embodiment of the present invention provides a ducted thrust turbofan, which includes: a blade hub 3, a turbofan blade 1, and a ducted housing 4 from the inside to the outside, and the turbofan blade 1 includes There are multiple; the inner side of each turbofan blade 1 is seamlessly connected with the outer sidewall of the blade hub 3, and the outer side is seamlessly connected with the inner sidewall of the duct casing 4, and each turbofan blade 1 is along the axial direction of the blade hub 3 Direction spirals from one end to the other.

Compared with the prior art, the ducted thrust turbofan described in the embodiment of the present invention has the following advantages:

In the ducted thrust turbofan provided by the embodiment of the present invention, as shown in Figure 1 and Figure 2, it includes: a blade hub 3, a turbofan blade 1 and a ducted casing 4 from the inside to the outside, and the turbofan blade 1 includes There are multiple; the inner side of each turbofan blade 1 is seamlessly connected with the outer sidewall of the blade hub 3, and the outer side is seamlessly connected with the inner sidewall of the duct casing 4, and each turbofan blade 1 is along the axial direction of the blade hub 3 Direction spirals from one end to the other. From this analysis, it can be seen that in the ducted thrust turbofan provided by the embodiment of the present invention, since the inner side of each turbofan blade 1 is seamlessly connected with the outer side wall of the blade hub 3, and the outer side is seamlessly connected with the inner side wall of the ducted casing 4 connected, and each turbofan blade 1 spirally extends from one end to the other end along the axial direction of the blade hub 3, so a completely closed spiral cavity 5 can be formed, so that there is no additional resistance when the air rotates at high speed in it , the air working medium will not overflow under the strong centrifugal force, and the end of the turbofan blade 1 will not be able to generate eddy currents or shock waves, which can effectively improve mechanical efficiency and reduce working noise.

In addition, in the ducted thrust turbofan provided by the embodiment of the present invention, since the inner side of each turbofan blade 1 is seamlessly connected with the outer sidewall of the blade hub 3, and the outer side is seamlessly connected with the inner sidewall of the ducted casing 4, and Each turbofan blade 1 spirally extends from one end of the axial direction of the blade hub 3 to the other end, so the overall structural strength of the ducted thrust turbofan is extremely high, so that the blade hub 3, the turbofan blade 1 and the ducted The shell 4 is as lightweight as possible, such as using high-strength composite materials or using 3D printing technology for one-time molding.

What needs to be added here is that, by Newton's second law (F=ma), it can be seen that after the air is sucked into the turbofan port by the air inlet 6, it will undergo continuous rotational acceleration in the spiral cavity 5, and finally with a great The speed is ejected from the jet port 7, which can convert the external power into thrust to the greatest extent.

In practical application, in order to realize the driving of the blade hub 3, the turbofan blade 1 and the duct casing 4, as shown in Figure 1, in the ducted thrust turbofan provided by the embodiment of the present invention, the center of the above-mentioned blade hub 3 is along A shaft hole 2 is opened in the axial direction, and the shaft hole 2 can be used to connect a driving device, such as a motor, so that the blade hub 3 is driven to rotate through a driving device such as a motor, and then drives the turbofan blade 1 and the duct casing 4 together turn.

Among them, in order to effectively improve the mechanical efficiency, as shown in Figure 1, in the ducted thrust turbofan provided by the embodiment of the present invention, one end of each turbofan blade 1 is seamlessly fixed on the blade hub 3, and the starting surface The normal line is facing the axis of the blade hub 3, and spirally extends downward at an attack angle of 40°-45°, and the other end of the formed turbofan surface is seamlessly fixed on the duct casing 4. According to theoretical calculations and test data statistics, the spiral downward extension of the turbofan blade 1 at an angle of attack of 40°-45° can better ensure a relatively high level of mechanical efficiency.

Specifically, as shown in FIG. 1 , in the ducted thrust turbofan provided by the embodiment of the present invention, the above-mentioned angle of attack may preferably be 45°.

Further, in order to reduce the rotational speed of the turbofan as much as possible and reduce the working noise, as shown in FIG. 1 , in the ducted thrust turbofan provided by the embodiment of the present invention, the above-mentioned turbofan blades 1 may include 10-20 pieces. According to theoretical calculations and test data statistics, the turbofan blades 1 with 10-20 pieces can better reduce working noise.

Furthermore, as shown in FIG. 1 , in the ducted thrust turbofan provided by the embodiment of the present invention, the number of the above-mentioned turbofan blades 1 may preferably be 10.

Meanwhile, in the ducted thrust turbofan provided by the embodiment of the present invention, the number of the above-mentioned turbofan blades 1 is not only limited to 10-20 pieces, but other reasonable values are acceptable according to actual needs.

Wherein, as shown in FIG. 1 and FIG. 2 , in the ducted thrust turbofan provided by the embodiment of the present invention, the ratio of the axial length of the blade hub 3 to the diameter of the ducted casing 4 may preferably be 2:1.

At the same time, in the ducted thrust turbofan provided by the embodiment of the present invention, the ratio of the axial length of the above-mentioned blade hub 3 to the diameter of the ducted casing 4 is not limited to 1:1-3:1. , and other reasonable values are acceptable.

Specifically, in order to effectively protect the ducted thrust turbofan, in the ducted thrust turbofan provided in the embodiment of the present invention, an outer fairing may also be provided on the outer side of the ducted casing 4 .

Compared with the prior art, the ducted thrust turbofan provided by the embodiment of the present invention mainly has the following advantages:

1. Since the inner side of each turbofan blade 1 is seamlessly connected to the outer side wall of the blade hub 3, and the outer side is seamlessly connected to the inner side wall of the duct casing 4, and each turbofan blade 1 is along the axial direction of the blade hub 3 One end of the spiral extends to the other end, so a completely closed spiral cavity 5 can be formed, so that there is no additional resistance when the air rotates at high speed in it, and the air working medium will not overflow under the strong centrifugal force, and the vortex There is no way to generate eddy current or shock wave at the end of fan blade 1, which can effectively improve mechanical efficiency and reduce working noise;

2. Since the inner side of each turbofan blade 1 is seamlessly connected to the outer side wall of the blade hub 3, and the outer side is seamlessly connected to the inner side wall of the duct casing 4, and each turbofan blade 1 is along the axial direction of the blade hub 3 One end of the ducted thrust turbofan spirally extends to the other end, so the overall structural strength of the ducted thrust turbofan is extremely high, so that the blade hub 3, the turbofan blade 1 and the ducted casing 4 can be lightened as much as possible, such as using high-strength composite materials Or use 3D printing technology to form at one time;

3. From Newton’s second law (F=ma), it can be seen that after the air is sucked into the turbofan port by the air inlet 6, it undergoes continuous rotational acceleration in the spiral cavity 5, and is finally sprayed by the air nozzle 7 at a great speed. out, the external power can be converted into thrust to the greatest extent.

The above description is only the best embodiment of the present invention, and is not intended to limit other designs of the present invention; within the design concepts and principles of the present invention, any modifications, equivalent replacements, improvements, etc. Included within the protection scope of the present invention.

Claims (9)

1. A ducted thrust turbofan, characterized in that it comprises sequentially from the inside to the outside: a blade hub, a turbofan blade and a ducted casing, and the turbofan blades include a plurality; The inner side of each turbofan blade is seamlessly connected with the outer sidewall of the blade hub, and the outer side is seamlessly connected with the inner sidewall of the duct casing, and each turbofan blade is connected along the axis of the blade hub Helix extending from one end of the direction to the other. 2 . The ducted thrust turbofan according to claim 1 , wherein a shaft-through hole is opened in the center of the blade hub along the axial direction, and the shaft-through hole is used for connecting a driving device. 3 . 3. The ducted thrust turbofan according to claim 1 or 2, characterized in that, one end of each turbofan blade is seamlessly fixed on the blade hub, and the normal of the starting surface faces all The shaft center of the blade hub is extended downward in a spiral manner at an angle of attack of 40°-45°, and the other end of the formed turbofan surface is seamlessly fixed on the duct shell. 4. The ducted thrust turbofan according to claim 3, wherein the angle of attack is 45°. 5. The ducted thrust turbofan according to claim 1 or 2, wherein the turbofan blades include 10-20 pieces. 6. The ducted thrust turbofan according to claim 5, wherein the turbofan blades comprise 10 pieces. 7. The ducted thrust turbofan according to claim 1 or 2, wherein the ratio of the axial length of the blade hub to the diameter of the ducted shell is 1:1-3:1. 8 . The ducted thrust turbofan according to claim 7 , wherein the ratio of the axial length of the blade hub to the diameter of the ducted shell is 1:1. 9 . The ducted thrust turbofan according to claim 1 , wherein an outer fairing is provided on the outer side of the ducted casing. 10 .