CN117450109A - Compressor stator cascade with V-shaped rib array arranged on the end wall of the channel - Google Patents

Abstract

The invention belongs to the technical field of compressor stator blade cascade flow control, and in particular relates to a compressor stator blade cascade with a V-shaped small rib array arranged on the end wall of a channel, which comprises a plurality of end walls of the channel, stator blades and blade root front edges, wherein the stator blades and the blade root front edges are arranged on the end walls of the channel, and a plurality of inclined small rib groups which are sequentially connected end to end are transversely arranged on the end wall of the channel and close to the blade root front edges; the small oblique rib groups are alternately arranged in a left-inclined mode and a right-inclined mode to form a V-shaped small rib array, and a plurality of parallel small oblique ribs are arranged on each small oblique rib group. The number of the oblique small rib groups in the V-shaped small rib array is 2-6, the number of the oblique ribs is 6-19, and the oblique ribs are arranged in parallel along the camber line of the stator blade in the tangential direction of the front edge of the blade root. The invention can inhibit the separation of the boundary layer and the formation of the channel vortex in the corner area while almost introducing no additional loss, thereby effectively inhibiting the separation of the stator blade cascade corner area of the compressor.

Description

Compressor stator cascade with V-shaped rib array arranged on the end wall of the channel

Technical field

The invention belongs to the technical field of compressor stator cascade flow control, and specifically relates to a compressor stator cascade in which a V-shaped rib array is arranged on the channel end wall.

Background technique

The requirement of aeroengines for high thrust-to-weight ratio drives the development of compressors toward high loads and low aspect ratios. The increase in stage load is reflected in the enhancement of the axial reverse pressure gradient and the transverse pressure gradient, which cause the low-energy fluid in the channel to accumulate toward the suction surface of the cascade and the end wall corner area, thus inducing corner area separation. Flow separation in the corner area will lead to channel blockage, blade load and reduction in expansion capacity, resulting in total pressure loss and efficiency decline. In severe cases, it may cause engine stall and surge. Therefore, trying to suppress the angular separation of the compressor is crucial to improving the performance and operating safety of the compressor.

At present, flow control technology for compressor stator cascade angle separation can be divided into two categories: active control and passive control. Active flow control technology requires a certain amount of energy to be injected from the outside to control the flow field. It mainly includes boundary layer suction technology, plasma excitation technology, synthetic jet, etc. Active control technology requires monitoring the operating status of the compressor and relying on additional adjustments. Mechanism-controlled flow separation is difficult to promote in engineering applications; passive flow control technology does not need to obtain energy from the outside world and relies on structural design to achieve the purpose of flow control. It mainly includes vortex generators, wing blades, blade root slots, and end wall shapes. etc., traditional vortex generators with blade-shaped or wedge-shaped structural features will also introduce additional losses to varying degrees while controlling the angular separation. How to find a balance between aerodynamic gain and additional losses has always been a need for passive control methods. Break through technical bottlenecks.

Contents of the invention

The object of the present invention is to provide a compressor stator cascade with a V-shaped rib array arranged on the channel end wall, which can suppress boundary layer separation and the formation of corner channel vortices while introducing almost no additional losses, thereby effectively suppressing the compressor Stator cascade corner separation.

The technical solutions adopted by the present invention are as follows:

A compressor stator cascade with a V-shaped rib array arranged on the channel end wall, including a plurality of channel end walls, stator blades and blade root leading edges arranged on the channel end wall, the channel end wall being close to the blade root leading edge A plurality of oblique small rib groups connected end to end are provided along the transverse direction;

The oblique small rib groups are arranged alternately in "left-leaning" and "right-leaning" directions to form a V-shaped small rib array, and each of the oblique small rib groups is provided with a plurality of parallel oblique ribs.

The number of oblique rib groups in the V-shaped rib array is 2-6, the number of oblique ribs is 6-19, and the oblique ribs are located at the blade root along the center arc of the stator blade. The tangent directions at the front edge are arranged parallel.

The vertical distance d ₁ between the lower boundary of the V-shaped rib array and the tangent line of the central arc of the stator blade at the leading edge of the blade root is 0.04l-0.06l;

The distance _d2 in the tangential direction between the trailing edge of the V-shaped rib array and the leading edge of the blade root of the stator blade is 0-0.2l;

Among them, l is the chord length of the stator blade.

The angle β between the extension direction of the oblique ribs and the tangent direction of the stator blade center arc at the blade root leading edge is 30°-60°.

The width W of each oblique small rib group is 0.2δ-0.4δ;

Among them, δ is the thickness of the boundary layer of the channel end wall.

The cross section of the oblique rib is triangular, with a height h of 0.06δ-0.14δ and a base m of 0.06δ-0.12δ.

The technical effects achieved by the present invention are:

The compressor stator cascade of the present invention in which a V-shaped rib array is arranged on the end wall of the stator channel can stir the airflow in the separation zone through the induced vortex array generated by the V-shaped array. The high-energy airflow in the upper part of the boundary layer can be mixed with the low-energy airflow near the wall to increase the momentum and energy of the near-wall fluid, thereby delaying downstream separation; on the other hand, the induced vortex array generated by the V-shaped array is used to block the cascade pressure surface The low-energy fluid accumulates in the corner area of the suction surface of the blade, delaying and weakening the channel vortex, thereby achieving the purpose of controlling separation in the corner area.

Compared with the traditional "vortex generator", the compressor stator cascade in which a V-shaped small rib array is arranged on the channel end wall of the present invention is used. The V-shaped small rib array used in the present invention utilizes the accumulation effect of multiple micro-vortex generators. Large-scale and high-intensity induced vortices are accumulated downstream, so the geometric size can be smaller than that of traditional vortex generators, and the resulting additional losses are also smaller; on the other hand, the V-shaped rib array used in the present invention is made of multiple It is composed of "left-leaning" and "right-leaning" oblique small rib groups, so it can generate induced vortex arrays with the same intensity and opposite directions downstream. Compared with the traditional single vortex generator, the gain effect of the present invention is more obvious.

Description of the drawings

Figure 1 is a schematic structural diagram of a V-shaped rib array arranged on the end wall of a channel according to an embodiment of the present invention;

Figure 2 is a partial schematic diagram of the geometric distribution of the V-shaped rib array according to the embodiment of the present invention;

Figure 3 is a schematic cross-sectional structural diagram of a V-shaped rib array according to an embodiment of the present invention;

Figure 4 is a limit streamline diagram of the end wall and suction surface of the prototype stator cascade according to the embodiment of the present invention;

Figure 5 is a limit streamline diagram of the end wall and suction surface of the stator cascade with a V-shaped rib array on the channel end wall according to the embodiment of the present invention;

Among them, the angle of attack is 4°;

Figure 6 is a comparison chart of performance parameters between a stator cascade with a V-shaped rib array and a prototype stator cascade according to the embodiment of the present invention.

In the drawings, the parts represented by each number are listed as follows:

1. Stator blade; 2. Channel end wall; 3. Blade root leading edge; 4. V-shaped array of small ribs; 5. Oblique ribs.

Detailed ways

In order to make the purpose and advantages of the present invention more clear, the present invention will be described in detail below with reference to examples. It should be understood that the following text is only used to describe one or several specific implementations of the present invention, and does not strictly limit the protection scope of the specific claims of the present invention.

As shown in Figures 1 to 6, a compressor stator cascade with a V-shaped array of small ribs arranged on the channel end wall includes a compressor stator cascade with a V-shaped array of small ribs arranged on the channel end wall, a plurality of channel end walls 2 and a set of On the stator blade 1 and the blade root leading edge 3 on the channel end wall 2, a plurality of oblique small rib groups connected end to end are arranged transversely on the channel end wall 2 and close to the blade root leading edge 3;

The oblique small rib groups are arranged alternately in "left-leaning" and "right-leaning" directions to form a V-shaped small rib array 4, and each of the oblique small rib groups is provided with a plurality of parallel oblique ribs 5.

The number of oblique rib groups in the V-shaped rib array 4 is 2-6, the present invention selects 4, the number of the oblique ribs 5 is 6-19, the present invention selects 11, and The oblique ribs 5 are arranged in parallel along the central arc line of the stator blade 1 in the tangential direction at the blade root leading edge 3 to form an array.

The vertical distance between the lower boundary of the V-shaped rib array 4 and the tangent line of the central arc of the stator blade 1 at the blade root leading edge 3 is d ₁ which is 0.04l-0.06l; in the present invention, the selected distance d ₁ is 0.04l;

The distance d2 in the tangential direction between the trailing edge of the V-shaped rib array 4 and the blade root leading edge 3 of the stator blade 1 is 0-0.2l; in the present invention, the distance _d2 is selected to be 0.05l;

Among them, l is the chord length of stator blade 1.

The angle β between the extending direction of the oblique ribs 5 and the tangent direction of the central arc of the stator blade 1 at the blade root leading edge 3 is 30°-60°. In the present invention, the angle β is selected to be 30°;

The width W of each oblique small rib group is 0.2δ-0.4δ; in the present invention, the width W is selected to be 0.25δ;

Among them, β is the thickness of the boundary layer of the channel end wall 2.

As shown in Figure 3, the cross-section of the oblique rib 5 is triangular, and the height h is 0.06δ-0.14δ. In the present invention, the height h is selected to be 0.08δ; the base m is 0.06δ-0.12δ. In the present invention Select the base m as 0.07δ.

Verification example:

In order to verify the effect of the present invention, the present invention conducts numerical simulations on a prototype compressor stator cascade and a compressor stator cascade with a V-shaped rib array 4 on the channel end wall 2 provided by the present invention. The specific simulation parameters and results are as follows:

The prototype stator cascade blade profile parameters used for simulation are shown in the following table:

As shown in Figures 4 and 5, by comparing the limiting streamline diagram of the wall surface of the prototype compressor stator cascade with the limiting streamline diagram of the wall surface of the compressor stator cascade of the channel end wall 2 provided by the present invention with a V-shaped rib array 4 , it can be found that after setting up the V-shaped small rib array 4, the lateral migration flow of low-energy fluid near the pressure surface of the cascade to the corner area of the suction surface of the cascade is effectively blocked, and the separation point in the end wall corner area moves back significantly, and the suction surface of stator blade 1 The separation range is significantly reduced, and the separation in the corner area of the blade cascade is significantly improved. Therefore, the arrangement of the V-shaped rib array 4 can delay and suppress the occurrence of separation in the corner area.

As shown in Figure 6, through the comparison results of the total pressure loss coefficient of numerical simulation, the compressor stator cascade with V-shaped rib array 4 on the channel end wall 2 provided by the present invention is comparable to the prototype compressor stator cascade. Compared with the above, the total pressure loss has been effectively improved in the entire stable operating range. The optimal effect can be obtained when the angle of attack is 4°, and the total pressure loss coefficient is reduced by 13.2%.

It can be seen that the compressor stator cascade with V-shaped rib array 4 arranged on the channel end wall 2 provided by the present invention can, on the one hand, stir the airflow in the separation zone through the induced vortex array generated by the V-shaped rib array 4, so that the boundary layer The high-energy airflow in the upper part can mix with the low-energy airflow near the wall to increase the momentum and energy of the near-wall fluid, thereby delaying the downstream separation; on the other hand, the induced vortex array generated by the V-shaped small rib array 4 is used to block the cascade pressure surface. The accumulation of low-energy fluid into the corner area of the blade suction surface delays and weakens the channel vortex, thereby achieving the purpose of controlling separation in the corner area.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be made. regarded as the protection scope of the present invention. The structures, devices and operating methods that are not specifically described and explained in the present invention are all implemented according to conventional means in the art unless otherwise specified or limited.

Claims (8)

1. A compressor stator cascade with a V-shaped rib array arranged on the channel end wall, which is characterized by: including a plurality of channel end walls (2) and stator blades (1) and blade roots arranged on the channel end wall (2) On the leading edge (3), a plurality of oblique small rib groups connected end to end are arranged in the transverse direction on the end wall of the channel (2) and close to the blade root leading edge (3); The oblique small rib groups are arranged alternately with "left tilt" and "right tilt" to form a V-shaped small rib array (4), and each of the oblique small rib groups is provided with a plurality of parallel oblique ribs ( 5). 2. The compressor stator cascade with a V-shaped rib array arranged on the channel end wall according to claim 1, characterized in that: the number of oblique rib groups in the V-shaped rib array (4) is 2- 6. 3. The compressor stator cascade with a V-shaped rib array arranged on the channel end wall according to claim 1, characterized in that the number of the oblique ribs (5) is 6-19. 4. The compressor stator cascade with a V-shaped rib array arranged on the channel end wall according to claim 1, characterized in that: the lower boundary of the V-shaped rib array (4) and the central arc line of the stator blade (1) The vertical distance d ₁ of the tangent line at the leading edge of the blade root (3) is 0.04l-0.06l; The distance d2 in the tangential direction between the trailing edge of the V-shaped rib array (4) and _the blade root leading edge (3) of the stator blade (1) is 0-0.2l; Among them, l is the chord length of the stator blade (1). 5. The compressor stator cascade with a V-shaped rib array arranged on the channel end wall according to claim 1, characterized in that: the extension direction of the oblique ribs (5) is in line with the central arc line of the stator blade (1). The angle β between the tangent directions at the blade root leading edge (3) is 30°-60°. 6. The compressor stator cascade with a V-shaped rib array arranged on the channel end wall according to claim 1, characterized in that: the width W of each oblique rib group is 0.2δ-0.4δ; Among them, δ is the thickness of the boundary layer of the channel end wall (2). 7. The compressor stator cascade with a V-shaped small rib array arranged on the channel end wall according to claim 1, characterized in that: the cross section of the oblique rib (5) is triangular, and the height h is 0.06δ-0.14 δ, the base m is 0.06δ-0.12δ. 8. The compressor stator cascade with a V-shaped rib array arranged on the channel end wall according to claim 1, characterized in that: the oblique ribs (5) are formed along the central arc of the stator blade (1) at the blade root. The front edge (3) is arranged parallel to the tangent direction.