Gas compressor rotor blade for flow control and design method thereof

Abstract

The invention provides a compressor rotor blade for flow control, the blade comprises a suction surface and a pressure surface, the suction surface and the pressure surface are two opposite side surfaces, and a suction hole is arranged in a root angle area on the suction surface; the blade tip side face of each blade is provided with a release hole, and the blade tip side face is connected between the suction face and the pressure face and away from the root. Cavities are formed in the blades and comprise gas flow channels, and the suction holes communicate with the release holes through the gas flow channels.

Description

Technical Field

[0001] This invention relates to the field of compressor rotor blade design, and more particularly to a compressor rotor blade for flow control and its design method. Background Technology

[0002] Compressor design increasingly pursues high efficiency and high load. With the rapid increase of load, the rotor blades of high-pressure compressors are prone to flow separation at the root under the action of reverse pressure gradient, forming a complex flow structure, which reduces the efficiency of the compressor and may even induce compressor stall.

[0003] To address this harmful flow phenomenon, active and passive control methods can be employed to control flow separation at the blade root. Commonly used active control methods include boundary layer suction technology, which primarily suppresses boundary layer separation by using ejectors or other external excitation sources, removing low-energy stall fluid from the blade root, and improving flow conditions at the blade root. This method offers significant control effects and strong adaptability. However, due to the rotating rotor, it is difficult to install suction devices, which also require additional power units and control systems, resulting in complex structures and high costs. Passive control methods do not require any external energy input. They achieve flow control by modifying the geometry of some blades to improve the flow field structure on the compressor blade surface. For stator blades, a bow-shaped blade design is often used, utilizing their radial migration capability to divert low-energy fluid from the blade root to the middle section where it is carried away by the main fluid. However, for rotor blades, the high rotational speed and large centrifugal force make it difficult to achieve a large bow angle at the blade root from a structural strength perspective, thus failing to effectively control flow losses at the rotor blade root.

[0004] Therefore, how to effectively control flow separation on rotor blades under high load is one of the key issues in compressor design. Summary of the Invention

[0005] The objective of this invention is at least to provide a compressor rotor blade for flow control, which can effectively draw low-energy fluid from the boundary layer of the rotor blade and improve flow separation in the blade corner region.

[0006] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0007] One embodiment of the present invention provides a compressor rotor blade for flow control. The blade includes a suction surface and a pressure surface, which are two opposing sides. A suction hole is provided in the root corner region of the suction surface. A release hole is provided on the blade tip side, which is a side connected between the suction surface and the pressure surface and away from the root. The blade has a cavity inside, which includes a gas flow channel. The suction hole and the release hole are connected through the gas flow channel.

[0008] In some embodiments, the suction port is located near the trailing edge of the blade.

[0009] In some embodiments, suction holes are provided in different regions within the root corner area according to the different total pressure loss coefficients on the suction surface.

[0010] In some embodiments, the suction holes provided in the same region within the root corner area include strip-shaped holes.

[0011] In some embodiments, the width of the orifice is positively correlated with the total pressure loss coefficient corresponding to that region.

[0012] In some embodiments, the width of the slot is 1mm to 8mm.

[0013] In some embodiments, the suction holes provided in the same area within the root corner region include a plurality of holes.

[0014] In some embodiments, the diameter of the hole is 1 mm to 10 mm.

[0015] In some embodiments, the density of the distribution of several holes is positively correlated with the total pressure loss coefficient of the corresponding area.

[0016] In some embodiments, a plurality of release holes are provided on the side of the blade tip, and the plurality of release holes are distributed along the chord length of the side of the blade tip.

[0017] In some embodiments, the diameter of the plurality of release holes is 0.5 mm to 3 mm.

[0018] In some embodiments, a plurality of suction holes are provided in the root corner area of ​​the suction surface, and all suction holes are connected to all release holes through the gas flow channel inside the blade.

[0019] This specification also provides a design method for compressor rotor blades for flow control, used to obtain the aforementioned compressor rotor blades, including: determining the setting area of ​​suction holes based on the total pressure loss coefficient at various points on the suction surface; setting suction holes in the setting area and setting release holes on the blade tip side; setting gas flow channels in the cavity inside the blade, the gas flow channels being used to connect the suction holes and the release holes.

[0020] In some embodiments, suction holes are set along the total pressure loss coefficient contour lines based on the total pressure loss coefficient contour lines within the set area.

[0021] In some embodiments, the suction orifice includes a plurality of holes distributed along the contour lines of the total pressure loss coefficient.

[0022] In some embodiments, the suction orifice includes a strip-shaped orifice that extends along the contour line of the total pressure loss coefficient.

[0023] This invention proposes a compressor rotor blade for flow control. By incorporating a suction port at the root corner of the suction surface and a release port on the blade tip side, the suction and release ports are connected by a gas channel within the blade. Under centrifugal force, the suction port draws in low-energy fluid from the boundary layer of the suction surface, improving flow in the corner region. The drawn-in fluid is released through the release port, effectively sealing the blade tip and suppressing leakage flow from the pressure surface to the suction surface at the blade tip, thus improving the flow field at the blade tip. This invention effectively removes low-energy fluid from the root corner of the rotor blade, significantly reducing flow losses at the blade root under high-load designs and improving surge margin. Simultaneously, the low-energy fluid is energized by centrifugal force within the rotor blade and flows out from the blade tip. The boundary layer fluid suction design of this invention does not introduce additional suction units, resulting in low manufacturing costs, ease of processing, and good suitability for engineering applications. Attached Figure Description

[0024] The above-described features and advantages of the present invention will be better understood after reading the following detailed description of the embodiments of this disclosure in conjunction with the accompanying drawings. In the drawings, components are not necessarily drawn to scale, and components having similar related characteristics or features may have the same or similar reference numerals. Wherein:

[0025] Figure 1 This is a flowchart illustrating a design method for compressor rotor blades for flow control, based on some embodiments.

[0026] Figure 2 This is a contour map of the total pressure loss coefficient of the existing suction surface;

[0027] Figure 3 This is a schematic diagram showing the distribution of suction holes on the suction surface according to some embodiments;

[0028] Figure 4 This is a schematic diagram showing the distribution of release holes on the side of the blade tip according to some embodiments;

[0029] Figure 5 This is a schematic diagram of the internal gas flow channel of the blade, based on some embodiments;

[0030] Figure 6This is a contour plot of the total pressure loss coefficient of the suction surface of a compressor rotor blade for flow control, based on some embodiments.

[0031] Figure 7 It is a streamline diagram of the existing blade tip;

[0032] Figure 8 This is a streamline diagram of the blade tip of a compressor rotor blade for flow control, as shown in some embodiments. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0034] It should be understood that the terms “system,” “device,” “unit,” and / or “module” used herein are one method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other words can achieve the same purpose, they may be replaced by other expressions.

[0035] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0036] It is understood that the technical terms that may be used in the description of this specification, such as “center,” “longitudinal,” “lateral,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the implementation method and do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the invention.

[0037] The compressor rotor blades described in this specification have suction and pressure surfaces, which are opposite sides. The compressor rotor blades also have a tip side, which is the side connecting the suction and pressure surfaces and located away from the root. The root of the blade is the portion of the blade closest to the engine's main rotating shaft (e.g., high-pressure shaft, low-pressure shaft). During rotor blade operation, excessive load at the root can cause flow separation, forming complex flow structures, reducing compressor efficiency, and even inducing compressor stall. This specification provides a compressor rotor blade capable of flow control, increasing boundary layer kinetic energy, and controlling or delaying airflow separation on the blade's suction surface. The compressor rotor blades for flow control described in this specification at least... Figure 1 The design method shown is 100.

[0038] Figure 1 This is a flowchart illustrating a design method for compressor rotor blades for flow control, based on some embodiments. For example... Figure 1 As shown, the compressor rotor blade design method 100 involved in the embodiments of this specification includes the following steps.

[0039] Step 110: Determine the area for setting the suction holes based on the total pressure loss coefficient at various points on the suction surface.

[0040] Specifically, the region with a relatively high total pressure loss coefficient at the root of the blade's suction surface is designated as the area for setting the suction orifice. The total pressure loss coefficient at various points on the blade's suction surface can be referenced. Figure 2 As shown. It should be noted that, Figure 2 And the following Figure 3 and Figure 5 The image shows a portion of the suction surface of the blade near the trailing edge 240, which connects to the side of the blade tip (see [reference]). Figure 4 The edge of 230 shown (see Figure 230) Figure 4 As shown at 231).

[0041] like Figure 2 As shown, the total pressure loss coefficient of the root corner region on the suction surface 210 of the blade is significantly higher than that of other regions on the suction surface 210. The root corner region is the area near the apex angle of the blade at the root. The root corner region on the suction surface 210 with a significantly higher total pressure loss coefficient is located near the trailing edge 240 of the blade. In some embodiments, the root corner region 211 on the suction surface 210 with a significantly higher total pressure loss coefficient, i.e., the area where the suction hole is located, is approximately a fan-shaped region centered at the apex angle of the blade.

[0042] In some embodiments, the total pressure loss coefficient at various points on the suction surface is obtained through simulation calculations. Figure 2The total pressure loss coefficient of the suction surface shown is obtained through simulation calculations using the first-stage rotor blade of an aero-engine high-pressure compressor as an example. In some embodiments, the relevant dimensions of the suction orifice are determined based on the magnitude of the total pressure loss coefficient. In some embodiments, the total pressure loss coefficients of different regions within the root corner region 211 on the suction surface 210, where the total pressure loss coefficient is significantly higher, vary. Based on the different total pressure loss coefficients on the suction surface, suction orifices are provided in different regions within the root corner region 211, and the relevant dimensions of the suction orifices provided in each region are different. For example, as... Figure 2 As shown, there are at least three regions (0.12, 0.17, 0.2) with different total pressure loss coefficients in the root corner region 211 of the suction surface 210, and the relevant dimensions of the suction holes set in the three regions with different total pressure loss coefficients are different.

[0043] In some embodiments, the suction orifice is a regular or irregular shape, including but not limited to circles, squares, polygons, strips, and ellipses. In some embodiments, the suction orifice includes a plurality of holes; this specification uses a circular hole as an example. In some embodiments, the density of the plurality of holes is determined according to the magnitude of the corresponding total pressure loss coefficient. Specifically, the density of the plurality of holes is positively correlated with the corresponding total pressure loss coefficient. As an example only, the density of the plurality of holes in a region with a total pressure loss coefficient of 0.12 is less than the density of the plurality of holes on the contour line of a total pressure loss coefficient of 0.17. The density referred to here is related to the spacing between adjacent holes. In some embodiments, the size of the holes is positively correlated with the corresponding total pressure loss coefficient, and the diameter of the holes is 1 mm to 10 mm. As an example only, the diameter of the holes in a region with a total pressure loss coefficient of 0.12 is 1 mm to 8 mm, and the diameter of the holes in a region with a total pressure loss coefficient of 0.17 is 2 mm to 9 mm. In some embodiments, the suction orifice includes a strip-shaped orifice with a width of 1 mm to 8 mm, wherein the width of the strip-shaped orifice refers to its dimension in the width direction perpendicular to the extension direction of the strip-shaped orifice. By way of example only, the width of the strip-shaped orifice in the region with a total pressure loss coefficient of 0.12 is 1 mm to 6 mm, and the width of the strip-shaped orifice in the region with a total pressure loss coefficient of 0.17 is 2 mm to 7 mm.

[0044] In some embodiments, the contour lines of the total pressure loss coefficient at various points on the suction surface are obtained through simulation calculations, and the contour lines of the total pressure loss coefficient are as follows: Figure 2As shown. Based on the total pressure loss coefficient contour lines of the set area, suction holes are set along the total pressure loss coefficient contour lines within the set area. In some embodiments, the suction holes include several holes distributed along the total pressure loss coefficient contour lines. The density of the distribution of several holes along the total pressure loss coefficient contour lines varies depending on the magnitude of the corresponding total pressure loss coefficient. This is only an example, such as... Figure 2 As shown, the density of several holes distributed on the total pressure loss coefficient contour line with a total pressure loss coefficient of 0.12 is less than the density of several holes distributed on the total pressure loss coefficient contour line with a total pressure loss coefficient of 0.17. In some embodiments, the suction orifice includes a strip-shaped orifice extending along the total pressure loss coefficient contour line. In some embodiments, the arrangement of suction orifices in the region between the total pressure loss coefficient contour lines can be the same as the arrangement of suction orifices on the total pressure loss coefficient contour line located at its outer edge, or it can transition from the arrangement of suction orifices on the total pressure loss coefficient contour line located at its outer edge to the arrangement of suction orifices on the total pressure loss coefficient contour line located at its inner edge. For example, in the region between the total pressure loss coefficient contour lines 0.12 and 0.17, the arrangement of suction orifices is the same as the arrangement of suction orifices on the total pressure loss coefficient contour line 0.12. For example, in the region between the total pressure loss coefficient contour line 0.12 and the total pressure loss coefficient contour line 0.17, the arrangement of the suction holes transitions from the arrangement of suction holes on the total pressure loss coefficient contour line 0.12 to the arrangement of suction holes on the total pressure loss coefficient contour line 0.17. The transition of the arrangement refers to the gradual change of the relevant dimensions of the suction holes (such as the density of the hole distribution, the diameter of the holes, or the width of the strip holes).

[0045] In some embodiments of this specification, the size and density of the suction orifices are adaptively set based on the different total pressure loss coefficients of the suction surface. The total pressure loss coefficient characterizes the degree of flow separation on the suction surface; the larger the total pressure loss coefficient, the higher the degree of flow separation on the suction surface. By adaptively setting the size and density of the suction orifices, the working capacity of the suction orifices in each region of the root corner region 211 is adapted to the corresponding total pressure loss coefficient, thereby uniformly improving the flow separation in the root corner region 211.

[0046] Step 120: Set the suction hole in the designated area and the release hole on the side of the blade tip.

[0047] In some embodiments, based on the arrangement of the suction holes determined in step 110, the density and size of the suction holes are set according to different total pressure loss coefficients, and the suction holes are placed in the designated area. In some embodiments, a plurality of release holes are provided on the blade tip side surface, and the arrangement of the plurality of release holes needs to cover the entire blade tip side surface. In some embodiments, the plurality of release holes are distributed along the chord length of the blade tip side surface. It is understood that the arrangement of the suction holes and the release holes does not distinguish the order of placement.

[0048] Step 230: Set a gas flow channel in the cavity inside the blade. The gas flow channel is used to connect the suction port and the release port.

[0049] In some embodiments of this specification, a suction port is provided at the root corner region 211 of the suction surface, a release port is provided on the side of the blade tip, and a gas flow channel connecting the suction port and the release port is provided in the cavity inside the blade. Since the rotor blades are subjected to centrifugal force extending from the root to the tip during operation, the low-energy fluid on the suction surface is introduced into the gas flow channel inside the blade through the suction port under the action of centrifugal force and ejected from the release port at the blade tip. This reduces the flow loss caused by separation at the root corner region 211. Simultaneously, due to the pressure difference between the pressure surface and the suction surface, fluid will leak through the gap between the blade tip and the casing under the pressure difference. This leaking flow will shear and mix with the mainstream, causing blade blockage, reducing flow capacity, and leading to high entropy increase, which accounts for 30% of the total aerodynamic loss in the blade channel. By releasing the gas jet from the release port at the blade tip, the leaking flow loss at the blade tip can be effectively suppressed, thereby improving compressor efficiency.

[0050] In some embodiments, the compressor rotor blades are obtained through the design method 100. Figures 3-5 The compressor rotor blades shown are shown. Figure 3 This is a schematic diagram showing the distribution of suction holes on the suction surface according to some embodiments; Figure 4 This is a schematic diagram showing the distribution of release holes on the side of the blade tip according to some embodiments; Figure 5 This is a schematic diagram of the internal gas flow channel of the blade, based on some embodiments.

[0051] like Figures 3-5 As shown, a suction hole 212 is provided in the root corner region 211 on the suction surface 210, and the suction hole 212 is located near the trailing edge 240 of the blade. The location and arrangement of the suction hole 212 are determined through step 110 above. In some embodiments, the suction hole 212 provided in the same region within the root corner region 211 on the suction surface 210 includes a strip-shaped hole and several holes. The same region within the root corner region 211 refers to a region with approximately the same total pressure loss coefficient.

[0052] A plurality of release holes 232 are provided on the blade tip side surface 230. In some embodiments, the plurality of release holes 232 are distributed along the chord length of the blade tip side surface 230, so that the arrangement of the release holes 232 covers the entire blade tip side surface 230, and the fluid released from the release holes 232 also covers the entire blade tip side surface 230, interrupting the blade tip leakage flow, which can effectively suppress the blade tip leakage flow loss, thereby improving the compressor efficiency. In some embodiments, considering the structural strength of the blade, the diameter of the release holes is 0.5 mm to 3 mm (e.g., 1 mm to 2 mm).

[0053] The blade has an internal cavity, including a gas flow channel 250. Suction holes 212 and release holes 232 are connected through the gas flow channel 250. This specification does not limit the shape and structure of the gas flow channel 250. In some embodiments, the gas flow channel 250 connects all suction holes 212 and release holes 232. In some embodiments, to ensure the structural strength of the blade, the gas flow channel 250 includes a first cavity 251 and a second cavity (not shown in the figure). The first cavity 251 connects all release holes 232 and is located near the blade tip side 230. The second cavity connects all suction holes 212 and is located near the root corner region 211 of the suction surface. The first cavity 251 and the second cavity are connected by a pipe, the cross-sectional area of ​​which is smaller than the cross-sectional areas of the first cavity 251 and the second cavity.

[0054] Figure 6 This is a contour map of the total pressure loss coefficient of the suction surface of a compressor rotor blade, used for flow control, based on some embodiments. For example... Figure 6 As shown, application Figures 3-5 The compressor rotor blade structure shown has significantly eliminated the high total pressure region at the root corner of its suction surface 210, reducing flow losses at the blade root under high load design, significantly improving rotor efficiency, increasing surge margin, and delaying the occurrence of stall surge.

[0055] A release hole 232 is provided on the side 230 of the blade tip. Low-energy fluid on the surface of the suction surface 210 is introduced into the gas flow channel inside the blade through the suction hole 212 and is thrown out from the release hole 232 at the blade tip. The fluid thrown out at the blade tip can suppress leakage flow from the pressure surface 220 to the suction surface 210 at the rotor blade tip, thereby improving the flow capacity of the blade tip. Specifically, as follows Figure 7 and Figure 8 As shown, Figure 7 The streamline of the blade tip of an existing rotor blade is shown. The tip leakage flow 71 has strong circumferential momentum, where circumferential refers to the direction around the engine rotation axis. The tip leakage flow 71 flows out from the gap between adjacent blades, forming a secondary leakage flow, which brings strong tip leakage flow loss. Figure 8 The application is shown. Figures 3-5The compressor rotor blade structure shown has streamlined blade tip, and the circumferential momentum of the tip leakage flow 81 is significantly reduced. The tip leakage flow 81 flows out roughly along its own suction surface and cannot form a secondary leakage flow, effectively reducing tip flow loss and significantly improving the efficiency of the rotor blade.

[0056] The basic concepts have been described above. It is clear that the detailed disclosure above is merely illustrative and does not constitute a limitation of this specification, especially for those skilled in the art. Furthermore, unless expressly stated in the claims, the order of elements and sequences, the use of numbers and letters, or other names in this specification are not intended to limit the order of the processes and methods described herein. Although various examples of currently considered useful embodiments of the invention have been discussed in the foregoing disclosure, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. Rather, the claims are intended to cover all modifications and equivalent combinations that conform to the substance and scope of the embodiments described herein.

Claims

1. A compressor rotor blade for flow control, characterized in that, The blade includes a suction surface and a pressure surface, the suction surface and the pressure surface are two opposite sides, and a suction hole is provided in the root corner area of ​​the suction surface; The blade tip side is provided with a release hole, and the blade tip side is the side that connects between the suction surface and the pressure surface and is away from the root. The blade has a cavity inside, the cavity includes a gas flow channel, and the suction hole and the release hole are connected through the gas flow channel.

2. The compressor rotor blade for flow control according to claim 1, characterized in that, The suction hole is located near the trailing edge of the blade.

3. The compressor rotor blade for flow control according to claim 1, characterized in that, Based on the different total pressure loss coefficients on the suction surface, the suction holes are set in different regions within the root corner area.

4. The compressor rotor blade for flow control according to claim 3, characterized in that, The suction holes provided in the same region within the root corner area include strip-shaped holes.

5. The compressor rotor blade for flow control according to claim 4, characterized in that, The width of the strip-shaped hole is positively correlated with the total pressure loss coefficient corresponding to the region.

6. The compressor rotor blade for flow control according to claim 4, characterized in that, The width of the strip hole is 1mm to 8mm.

7. The compressor rotor blade for flow control according to claim 3, characterized in that, The suction holes provided in the same region within the root corner area include a plurality of holes.

8. The compressor rotor blade for flow control according to claim 7, characterized in that, The diameter of the hole is 1mm to 10mm.

9. The compressor rotor blade for flow control according to claim 7, characterized in that, The density of the distribution of the plurality of holes is positively correlated with the total pressure loss coefficient corresponding to the region.

10. The compressor rotor blade for flow control according to claim 1, characterized in that, The blade tip has several release holes on its side, and these release holes are distributed along the chord length of the blade tip side.

11. The compressor rotor blade for flow control according to claim 10, characterized in that, The diameter of the plurality of release holes is 0.5 mm to 3 mm.

12. The compressor rotor blade for flow control according to claim 10, characterized in that, Several suction holes are provided in the root corner area of ​​the suction surface, and all the suction holes are connected to all the release holes through the gas flow channel inside the blade.

13. A method for designing compressor rotor blades for flow control, characterized in that, For obtaining the compressor rotor blades according to any one of claims 1-12, comprising: Based on the total pressure loss coefficient at various points on the suction surface, the area where the suction hole is located is determined; The suction hole is set in the set area, and the release hole is set on the side of the blade tip; The gas flow channel is provided in the cavity inside the blade, and the gas flow channel is used to connect the suction port and the release port.

14. The design method for compressor rotor blades for flow control according to claim 13, characterized in that, Based on the contour lines of the total pressure loss coefficient within the set area, the suction holes are set along the contour lines of the total pressure loss coefficient.

15. The method for designing compressor rotor blades for flow control according to claim 14, characterized in that, The suction hole includes a plurality of holes, which are distributed along the contour lines of the total pressure loss coefficient.

16. The method for designing compressor rotor blades for flow control according to claim 14, characterized in that, The suction orifice includes a strip-shaped orifice that extends along the contour line of the total pressure loss coefficient.

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