A pneumatic groove jet structure based on rear axle neck cone wall cavity cooling gas supply

Abstract

The application relates to the technical field of turbine cooling of an aero-engine, in particular to an aerodynamic hole type jet structure based on rear shaft neck cone wall cavity cooling gas supply. The structure is arranged on a stator cone wall and penetrates the stator cone wall, the inlet of the structure is communicated with a gas supply chamber outside the stator cone wall, and the outlet is communicated with a rear shaft neck cone wall cavity; an aerodynamic hole channel continuously tapering from the inlet to the outlet is formed in the jet structure, the inlet section and the outlet section are both circular sections perpendicular to the central axis of the jet structure, the outlet section is the minimum flow passage section and constitutes a throat, and the inlet section and the outlet section are connected through smooth transition connection of a circular arc surface; the central axis of the jet structure is arranged obliquely relative to the stator cone wall, and the circumferential velocity direction of the outlet airflow is consistent with the rotating direction of the rotor cone wall. The stator cone wall is provided with a local thickening boss at the corresponding position of the jet structure, and the boss is integrally formed with the stator cone wall; a plurality of jet structures are uniformly arranged in a single row along the circumference of the stator cone wall.

Description

Technical Field

[0001] This application relates to the field of aero-engine turbine cooling technology, and more specifically, to an aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply. Background Technology

[0002] The most effective way to improve the performance of aero engines is to increase the temperature of the turbine inlet gas. Although the application of current materials technology has been pushed to its limit, there is still a certain gap between it and the temperature load level of advanced aero engines. The remaining cooling task needs to be undertaken by the efficient cooling technology of the secondary air system of aero engines. Reasonable and refined design of the air system flow path to fully explore the cooling potential of the bleed air flow is the key to ensuring the life and reliability of hot-end components of aero engines.

[0003] like Figure 1 As shown, the rotary-static system, represented by the conical wall cavity, CDP grating, and drum cavity, is the key flow path connecting the compressor stage bleed air with the turbine disk front rotary-static cavity. The bleed air method of the compressor rear journal conical wall cavity is orifice bleed air, as shown... Figure 1 As shown, airflow Figure 1 As shown by the arrow, the flow is introduced into the conical wall cavity 2 through the throttling orifice 1 of the stationary component. The cavity is formed by the stator conical wall 3 and the rotor conical wall 4. According to the pressure boundary conditions at the compressor stage outlet, the rim 5 is radially intruded or leaking. The airflow from the rim 5 and the throttling orifice 1 mixes in the conical wall cavity 2 and flows through the inclined conical wall in a radial inward manner to cool the rotor. The airflow continues to flow downstream to cool the downstream components, including the CDP grate element 6 and the drum cavity 7. The aerodynamic parameters of the airflow at the outlet of the throttling element 1 directly determine the quality of the cold air in the downstream cavity.

[0004] Currently, the traditional throttling scheme for the conical wall cavity is a simple straight hole structure. The cold air is injected into the conical wall cavity through the throttling straight hole 1, and its rotation ratio is approximately 0. There is a severe shearing effect between the cold air and the rotor wall, and the relative total temperature of the cold air rises rapidly. Although the straight hole scheme has a simple structure, its aerodynamic and thermodynamic performance is no longer sufficient to meet the high-efficiency cooling requirements of advanced engines.

[0005] To address the aforementioned issues, introducing a pre-swirl nozzle is an effective technical approach. The pre-swirl nozzle, through a specific profile, guides the flow, ensuring the injected cool gas has an appropriate rotation ratio, significantly reducing frictional temperature rise and optimizing pressure distribution within the disc cavity. Currently, various nozzle structures are applied to different parts of aero-engines, such as straight-hole and cascade types.

[0006] However, the existing solution has obvious limitations when directly transplanted to the rear axle journal cone wall cavity: the flow separation inside the straight hole nozzle is severe, the pre-swirl efficiency is low and the adaptability to different operating conditions is poor; although the blade cascade nozzle has good guidance, its structure is complex and it is difficult to arrange it in the narrow cavity of the oblique cone wall.

[0007] Therefore, there is an urgent need to design a new type of pre-swirling nozzle that combines aerodynamic efficiency, compact structure, and adaptability to the unique flow channel characteristics of the conical wall cavity, so as to fundamentally improve the cooling effect of this part. Summary of the Invention

[0008] In view of this, in order to solve the above-mentioned problems in the prior art, this application provides a pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply.

[0009] The embodiments of this application are implemented as follows: In a first aspect, this application provides a pneumatic orifice jet structure based on cooling air supply in a rear axle journal conical wall cavity, wherein the rear axle journal conical wall cavity is formed by a stator conical wall and a rotor conical wall opposite to the stator conical wall; The pneumatic orifice jet structure is disposed on and penetrates the stator cone wall. The inlet of the pneumatic orifice jet structure is connected to the air supply chamber on the outside of the stator cone wall, and the outlet of the pneumatic orifice jet structure is connected to the rear axle journal cone wall cavity. The stator cone wall is provided with an independent locally thickened protrusion at the corresponding position of each pneumatic orifice jet structure. The locally thickened protrusion is located on the outside of the stator cone wall and is integrally formed with the stator cone wall. The locally thickened protrusion is connected to the basic wall thickness area of ​​the stator cone wall on both sides along the meridional direction of the stator cone wall through a smooth transition contour. The pneumatic jet structure has an internal pneumatic channel that gradually narrows from the inlet to the outlet. The inlet and outlet sections of the pneumatic channel are both radial sections. The outlet section is the minimum flow section of the pneumatic channel and forms the throat. The inlet and outlet sections are smoothly connected by a circular arc surface, so that the flow cross-sectional area of ​​the pneumatic channel continuously decreases along the airflow direction. The central axis of the aerodynamic orifice jet structure is arranged at an inclination relative to the stator cone wall, and the circumferential velocity direction of the outlet airflow of the aerodynamic orifice jet structure is consistent with the rotation direction of the rotor cone wall.

[0010] In one possible implementation, the inlet diameter of the pneumatic channel is d 1. The outlet diameter is d 2, and d 1 greater than d 2. The inlet diameter d The value of 1 ranges from 5mm to 6mm, and the outlet diameter... d The value of 2 ranges from 2.5 mm to 3.0 mm; A first control length is provided along the central axis of the aerodynamic orifice jet structure. l 1 and second control length l2, used to define the relative positions of the inlet section, the outlet section, and the tapered surface located between the inlet section and the outlet section, the first control length l The value of 1 ranges from 4mm to 5mm, and the second control length l The value of 2 ranges from 6.5 mm to 7.5 mm; The profile of the pneumatic channel forms a control angle at its tapering section. i 3， The control angle i The value of 3 ranges from 20° to 40°.

[0011] In one possible implementation, the basic wall thickness of the stator cone wall... w The value of 1 ranges from 2mm to 3mm, and the total thickness of the locally thickened boss is... w The value of 2 ranges from 6mm to 7mm, and the radius of curvature of the smooth transition contour on both sides of the locally thickened boss is... r 1 and r The value range of 2 is 4mm to 4.5mm and 4.5mm to 5.0mm respectively.

[0012] In one possible implementation, within the meridional section of the stator cone wall, the angle between the projection of the central axis of the aerodynamic jet structure and the tangent of the stator cone wall at that location is . i 1, i 1 is 90°; Within the normal cross-section of the stator cone wall, the angle between the central axis of the aerodynamic jet structure and the tangent to the stator cone wall at that point is . i 2, i 2 is 20°; The angle between the central axis of the aerodynamic jet structure and the normal to the stator cone wall at that location is: α , α =90° - i 2, α It is 70°.

[0013] In one possible implementation, multiple aerodynamic jet structures are arranged in a single row at the same circumferential position along the stator cone wall, and the channel size, spatial tilt angle and outlet airflow direction of each aerodynamic jet structure are the same. The number of the pneumatic orifice jet structures is N The circumferential periodic angle between two adjacent aerodynamic jet structures is β , β =360° / N .

[0014] Secondly, this application provides a design method for an aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, used to realize the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in any of the above claims, including: S1: Obtain the structural parameters and operating conditions of the rear journal conical wall cavity of the aero-engine to be designed. The structural parameters include the spatial structure of the stator conical wall and the rotor conical wall, the flow channel size of the conical wall cavity, and the rotor speed. The operating conditions include the cooling gas requirements of the conical wall cavity, the supply pressure, the supply temperature, the pressure boundary, and the cooling requirements of downstream components. Based on the structural parameters and operating conditions, determine the cooling gas flow rate and pre-swirl degree that the aerodynamic orifice jet structure needs to meet. S2: Determine the number N of jet structures based on the spatial structure of the stator cone wall and the required cold air flow rate of the aerodynamic orifice jet structure, and arrange multiple aerodynamic orifice jet structures circumferentially along the stator cone wall. S3: Based on the spatial structure of the stator cone wall and the spatial arrangement requirements of the jet channel, an independent locally thickened protrusion is established at the corresponding position of each jet structure. The locally thickened protrusion is set on the gas supply side of the stator cone wall and forms an integral structure with the stator cone wall. The circumferential width, meridional length and transition profile of the locally thickened protrusion are determined according to the jet structure inlet diameter, jet structure spatial inclination angle, channel length and processing requirements, and the minimum remaining wall thickness around the jet structure channel is ensured to meet the strength requirements. S4: Determine the inlet diameter based on the required cooling air flow rate and system pressure ratio of the aerodynamic jet structure. d 1 and outlet throat diameter d 2. A circular pneumatic channel with a continuous tapering from the inlet to the outlet is constructed, wherein the inlet cross section and the outlet cross section are both radial cross sections of the pneumatic channel, and the outlet cross section serves as the minimum flow cross section of the flow channel. The system pressure ratio is determined based on the gas supply pressure and pressure boundary of the conical wall cavity. S5: Based on inlet diameter d 1. Outlet diameter d 2. The total length of the tapered flow channel is determined by the meridional length of the locally thickened protrusion, and a first control length is set along the central axis of the jet structure. l 1 and second control length l 2. This defines the relative positions of the inlet cross-section, outlet cross-section, and intermediate tapering surface, causing the flow channel cross-sectional area to continuously decrease along the direction of the cold air. A smooth transition is achieved between the inlet and outlet cross-sections using a circular arc surface. The first control length is determined based on the flow coefficient, internal flow separation, and manufacturing feasibility. l 1 and second control length l The specific value of 2, the first control length l 1 represents the distance from the start position to the end position of the tapered section, and the second control length.l 2 represents the distance from the starting position of the contraction section to the outlet section; the total length of the contraction channel is... l 1. And the total length does not exceed the meridional length of the locally thickened boss; S6: Establish a spatial orientation reference based on the local normal, centerline, and local tangent of the stator cone wall at the location of the jet structure; determine the spatial attitude of the centerline based on the target pre-spin direction; and determine the angle within the meridional section of the stator cone wall. i 1. Determine the angle within the normal section of the stator cone wall. i 2, and according to α =90° - i 2. Determine the pre-swirl space angle of the jet structure α This causes the outlet airflow to jet into the conical cavity and obtain a circumferential velocity component that is consistent with the rotor's rotation direction. S7: Establish a three-dimensional flow calculation model by combining the designed aerodynamic orifice jet structure with the stator cone wall, rotor cone wall, wheel rim and downstream components. Set the inlet pressure, temperature, cone wall cavity pressure boundary, rotor speed and flow boundary at wheel rim and drum cavity of the jet structure according to the actual engine working state, and perform aerodynamic performance calculation on the designed jet structure. S8: Evaluate the flow coefficient, pre-swirl efficiency, outlet flow direction, cold air rotation state in the cone wall cavity, relative velocity near the rotor cone wall, and cold air temperature rise index of the jet structure based on the aerodynamic performance calculation results. When all performance indicators meet the design requirements, determine the current structure as the target aerodynamic orifice jet structure. When any performance indicator fails to meet the design requirements, determine the corresponding adjustment parameters and return steps according to the type of the unmet indicator, and perform iterative correction.

[0015] In one possible implementation, when any performance metric fails to meet the design requirements, the corresponding parameters to be adjusted and the return steps are determined based on the type of the failed metric, and iterative correction is performed, specifically including: If the flow coefficient is lower than the design requirement, return to step S5 and adjust the first control length. l 1 or second control length l 2. After adjustment, re-execute S7 and S8; If the pre-spinning efficiency is lower than the design requirement, return to step S6 and adjust the pre-spinning angle. i 2. Pre-rotation space angle α or meridian angle i 1. After adjustment, re-execute S7 and S8; If the outlet flow direction deviates from the target direction, return to S6, redetermine the spatial attitude of the centerline, and re-execute S7 and S8 after adjustment; If the rotation state of the cold air in the cone wall cavity or the relative velocity near the rotor cone wall does not meet the standard, return to S4 and / or S6 to adjust the inlet diameter. d 1. Outlet diameter d 2 and / or pre-rotation angle i 2. After adjustment, re-execute S5, S7, and S8; If the temperature rise of the cold air along the path exceeds the design requirement, return to S6 and reduce the pre-swirl angle. i 2. After adjustment, re-execute S7 and S8; If the outlet flow rate of the jet structure does not meet the cooling demand, return to S7 and increase the inlet diameter. d 1 and outlet diameter d 2. After adjustment, re-execute S5, S7, and S8; If the adjustment amount in any step from S3 to S6 reaches the structural constraint boundary value and still cannot make all performance indicators meet the design requirements at the same time, return to S2, increase or decrease the number of jet structures N, and re-execute S3 to S8.

[0016] In one possible implementation, in step S6, the pre-rotation angle is determined based on the rotational speed of the rotor cone wall and the required rotation ratio. i 2. Expressed by the formula: ; in, β For the desired rotation ratio, Let be the circumferential linear velocity of the rotor cone wall at the radius of the jet structure outlet. , The rotor angular velocity, Let be the radius of the location at the center of the exit section of the jet structure. The resultant velocity of the airflow at the exit of the jet structure. β The value range is 0.7≤ β ≤1.1; when > When, reduce the pre-rotation angle i 2. To increase the circumferential velocity component of the airflow, when < At that time, increase the pre-rotation angle i 2. To reduce the circumferential velocity component of the airflow, so that the circumferential velocity component of the outlet airflow approaches... ; Pre-rotation angle i The constraint range of 2 is 10°≤ i 2≤30°, and i 2 and pre-spin space angle α satisfy α =90° - i 2; when At that time, the circumferential velocity component of the outlet airflow is equal to the circumferential linear velocity of the rotor cone wall, and the relative circumferential velocity between the cooling airflow and the rotor cone wall is zero.

[0017] In one possible implementation, the pre-rotation angle i The optimal value of 2 is determined by the following optimization function: ; Among them, the objective function is optimized. for: ; in, The resultant velocity of the airflow at the exit of the jet structure. This represents the circumferential velocity component of the outlet airflow. The circumferential linear velocity of the rotor cone wall is... This represents the total pressure loss at the inlet and outlet of the jet structure. The total pressure at the inlet of the jet structure. and These are the weighting coefficients, and These are used to adjust the weight ratio of pre-spin matching degree and flow loss in the optimization objective, respectively; when When the first term of the objective function is minimized, the circumferential velocity component of the outlet airflow approaches the circumferential linear velocity of the rotor cone wall. At this time, the relative circumferential velocity between the cooling airflow and the rotor cone wall approaches zero, the wall shearing effect is minimized, and the frictional temperature rise is minimized.

[0018] In one possible implementation, in step S3, the minimum remaining wall thickness around the jet structure channel is not less than 2 mm.

[0019] The technical solution provided in this application can achieve at least the following beneficial effects: This application provides a pneumatic jet structure for cooling air supply based on the rear axle journal cone wall cavity. By arranging the jet structure obliquely on the stator cone wall and connecting its outlet to the cone wall cavity, and forming a continuously tapering and smoothly transitioning aerodynamic channel inside, the outlet section forms a throat, effectively suppressing internal flow separation. Furthermore, by utilizing the spatial tilt angle of the jet structure, the outlet airflow obtains a circumferential velocity component consistent with the rotor rotation direction, significantly reducing the relative circumferential velocity and frictional temperature rise between the cooling airflow and the rotor cone wall.

[0020] Based on this, by setting d 1=5.4mm d 2 = 2.7mm (shrinkage ratio 2:1) l 1=4.4mm l 2=7.0mm and iThe combination of 3=30° orifice parameters allows the airflow to achieve smooth and sufficient acceleration within a limited channel length. The 2:1 contraction ratio ensures that the airflow reaches the optimal speed matching the rotor at the outlet throat. The control lengths of 4.4mm and 7.0mm limit the start and end positions of the tapering section and the overall channel length. The 30° control angle ensures the smoothness of the transition between the profile generatrix and the central axis. The synergistic effect of these parameters allows the airflow to achieve maximum kinetic energy conversion without separation within the channel, thereby increasing the flow coefficient to 0.897 and the pre-swirl efficiency to 0.898, which are 25.8% and 56.4% higher than those of traditional straight-hole nozzles, respectively, achieving optimal synergy between flow capacity and pre-swirl effect.

[0021] Meanwhile, by setting locally thickened bosses at corresponding positions on the stator cone wall and integrally forming them with the stator cone wall, and connecting them to the base wall thickness area on both sides in the meridional direction through smooth transition contours, the problem of insufficient wall thickness faced when opening inclined elongated holes in a thin-walled structure with a base wall thickness of only 2mm is solved. If a tapered channel with an inclination angle of 20° and an axial length exceeding 7mm is directly opened on the base wall thickness, the channel wall will penetrate the cone wall or result in an excessively small local wall thickness, failing to meet the strength requirements; while the 6.6mm local total thickness is combined with r 1=4.2mm r The smooth transition profile of 2=4.6mm provides ample machining space while avoiding stress concentration, making it possible to arrange the inclined tapering channels completely. Furthermore, the one-piece molding eliminates the risk of sealing and loosening in insert assembly, ensuring structural reliability.

[0022] Furthermore, in coordination i 1 = 90° i 2=20° α The 70° spatial angle setting ensures that the outlet airflow acquires a circumferential velocity component consistent with the rotor's rotation direction while radially entering the conical cavity. The 20° pre-swirl angle is a critical value determined through optimization based on the rotor speed and the geometric constraints of the conical cavity. If the angle is greater than this, the circumferential velocity component is insufficient, and the pre-swirl effect decreases. If the angle is less than this, the radial velocity component is excessively lost, affecting the cooling airflow's ability to be delivered radially inward and downstream. Simultaneously, combined with the scheme of 12 jet structures evenly arranged circumferentially, the total air supply flow rate meets the cooling requirements of the conical cavity and its downstream components while ensuring sufficient wall thickness between each jet structure to meet structural strength requirements. Furthermore, the circumferential uniformity ensures that the pre-swirl flow field within the conical cavity is axisymmetric and free from local eddies or flow dead zones.

[0023] Ultimately, the cooling airflow flows radially inward and downstream after passing through the conical wall cavity, which increases the temperature drop level at the drum cavity outlet. It maintains a high flow coefficient and high pre-swirl efficiency throughout the entire envelope, significantly improving the quality and reliability of the cooling air supply. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a conventional rear axle neck cone wall cavity, as illustrated in an exemplary embodiment of this application.

[0026] Figure 2 This is a schematic diagram of the structure of the cone wall cavity of the rear journal of an aero-engine employing a pneumatic orifice jet structure, as shown in an exemplary embodiment of this application.

[0027] Figure 3 This is a partial cross-sectional view of the meridional section of the cone wall cavity of a pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, as illustrated in an exemplary embodiment of this application.

[0028] Figure 4 This is a partial cross-sectional view of the stator cone wall normal section of an exemplary embodiment of this application illustrating a pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply.

[0029] Figure 5 This is a schematic diagram of the spatial position of a pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, as illustrated in an exemplary embodiment of this application.

[0030] Figure 6 This is a three-dimensional structural schematic diagram of a pneumatic orifice jet structure unit based on rear axle journal cone wall cavity cooling air supply, as shown in an exemplary embodiment of this application.

[0031] Figure 7 This is a bar chart comparing the performance parameters of the rear axle journal cone wall cavity using different throttling schemes, as illustrated in an exemplary embodiment of this application.

[0032] Figure 8 This is a schematic flowchart illustrating a design method for a pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, as shown in an exemplary embodiment of this application.

[0033] Figure 9 This is a schematic diagram comparing the meridional section airflow rotation ratio cloud diagram of an aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply and a traditional simple straight hole scheme, as shown in an exemplary embodiment of this application.

[0034] Figure 10This is a schematic diagram comparing the relative total temperature cloud map of the meridional section airflow of a pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, as shown in an exemplary embodiment of this application, with that of a traditional simple straight hole scheme.

[0035] Explanation of reference numerals in the attached drawings: 1. Pneumatic orifice jet structure; 2. Conical wall cavity; 3. Stator conical wall; 4. Rotor conical wall; 5. Rim; 6. CDP grate element; 7. Drum cavity. Detailed Implementation

[0036] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0037] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0038] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0039] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0040] Next, the technical solutions of this application and how they solve the aforementioned technical problems will be described in detail through embodiments and in conjunction with the accompanying drawings. The embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application.

[0041] In one exemplary embodiment, such as Figure 2 As shown, a pneumatic orifice jet structure based on rear axle journal conical wall cavity cooling air supply is provided. In this embodiment, the rear axle journal conical wall cavity is formed by a stator conical wall and a rotor conical wall opposite to the stator conical wall. The pneumatic orifice jet structure is disposed on and penetrates the stator cone wall. The inlet of the pneumatic orifice jet structure is connected to the air supply chamber on the outside of the stator cone wall, and the outlet of the pneumatic orifice jet structure is connected to the rear axle journal cone wall cavity. The stator cone wall is provided with an independent locally thickened protrusion at the corresponding position of each pneumatic orifice jet structure. The locally thickened protrusion is located on the outside of the stator cone wall and is integrally formed with the stator cone wall. The locally thickened protrusion is connected to the basic wall thickness area of ​​the stator cone wall on both sides along the meridional direction of the stator cone wall through a smooth transition contour. The pneumatic jet structure has an internal pneumatic channel that gradually narrows from the inlet to the outlet. The inlet and outlet sections of the pneumatic channel are both radial sections. The outlet section is the minimum flow section of the pneumatic channel and forms the throat. The inlet and outlet sections are smoothly connected by a circular arc surface, so that the flow cross-sectional area of ​​the pneumatic channel continuously decreases along the airflow direction. The central axis of the aerodynamic orifice jet structure is arranged at an inclination relative to the stator cone wall, and the circumferential velocity direction of the outlet airflow of the aerodynamic orifice jet structure is consistent with the rotation direction of the rotor cone wall.

[0042] In some embodiments, such as Figure 2 As shown, the flow path of the rear journal of the aero-engine compressor is mainly composed of the stator cone wall and the rotor cone wall opposite to the stator cone wall. The stator cone wall and the rotor cone wall enclose the rear journal cone wall cavity.

[0043] Downstream of the rear axle journal cone wall cavity, there are CDP toothed elements and a drum cavity. Cooling airflow from the compressor stage outlet is introduced into the rear axle journal cone wall cavity through a throttling structure on the stator cone wall. Radial intrusion or leakage occurs at the wheel rim. The airflow from the wheel rim and the throttling structure mixes in the rear axle journal cone wall cavity and then flows radially inward and downstream.

[0044] In this embodiment, the pneumatic orifice jet structure is disposed on and penetrates the stator cone wall, so that the air supply chamber on the outside of the stator cone wall is connected to the rear axle journal cone wall cavity.

[0045] Specifically, the inlet of the pneumatic orifice jet structure is located on the outer surface of the stator cone wall and communicates with the air supply chamber on the outer side of the stator cone wall. The outlet of the pneumatic orifice jet structure is located on the inner surface of the stator cone wall and communicates with the rear journal cone wall cavity. During operation, the cooling airflow from the air supply chamber on the outer side of the stator cone wall enters through the inlet of the pneumatic orifice jet structure, is accelerated through the internal flow channel of the jet structure, and is then injected into the rear journal cone wall cavity through the outlet of the jet structure, and flows radially inward and downstream along the rear journal cone wall cavity.

[0046] like Figure 3 and Figure 4As shown, the internal structure of the aerodynamic jet has an aerodynamic channel extending from the inlet to the outlet. The aerodynamic channel gradually narrows from the inlet to the outlet along the airflow direction, that is, its flow cross-sectional area continuously decreases along the airflow direction.

[0047] Specifically, the inlet section of the aerodynamic channel is a circular section perpendicular to the central axis of the aerodynamic jet structure, and the outlet section of the aerodynamic channel is also a circular section perpendicular to the central axis of the aerodynamic jet structure. The outlet section is the minimum flow section of the aerodynamic channel, forming the throat of the entire aerodynamic channel. The inlet section and the outlet section are smoothly connected by a circular arc surface, so that there are no sudden expansions, contractions, or obvious bends on the inner surface of the aerodynamic channel. The airflow can accelerate smoothly when flowing through the aerodynamic channel, avoiding flow separation caused by abrupt changes in the flow channel cross-section.

[0048] The aforementioned continuously tapering smooth arc surface design causes the cross-sectional area of ​​the pneumatic channel to decrease continuously from the inlet to the outlet along the airflow direction, and the airflow velocity gradually increases. After reaching the maximum velocity at the outlet throat, the airflow is injected into the rear axle journal cone wall cavity.

[0049] like Figure 5 As shown, the central axis of the aerodynamic orifice jet structure is arranged at an angle relative to the stator cone wall. In the normal section of the stator cone wall, the angle between the central axis of the aerodynamic orifice jet structure and the tangent of the stator cone wall at that point is the pre-rotation angle. By setting this tilt angle, the circumferential velocity direction of the outlet airflow of the aerodynamic orifice jet structure is consistent with the rotation direction of the rotor cone wall.

[0050] Therefore, when the cooling airflow is injected into the rear journal cone wall cavity through the aerodynamic jet structure, it not only has a radial velocity component toward the interior of the rear journal cone wall cavity, but also a circumferential velocity component along the rotor cone wall and in the same direction as the rotor rotation, thereby allowing the cooling airflow entering the rear journal cone wall cavity to be pre-swirled.

[0051] Compared to a simple straight hole structure without pre-swirl, the pneumatic orifice jet structure of this embodiment can reduce the relative circumferential velocity between the cooling airflow and the rotor conical wall, reduce the shearing effect and frictional temperature rise between the airflow and the rotor wall, and thus improve the cooling effect of the rear journal conical wall cavity and its downstream components.

[0052] like Figure 3 As shown, due to the inclined arrangement of the aerodynamic orifice jet structure relative to the stator cone wall, and the need for the aerodynamic channel to achieve a flow rate from the inlet diameter within a limited axial length, the aerodynamic orifice jet structure is designed to achieve a flow rate from the inlet diameter to the stator cone wall. d 1. Outlet diameter d The continuous contraction of 2 means that the aerodynamic channel needs to occupy a certain structural space inside the stator cone wall. In order to ensure the structural strength of the stator cone wall while ensuring the complete arrangement of the aerodynamic channel, the stator cone wall is provided with independent local thickening protrusions at the corresponding positions of individual aerodynamic jet structures.

[0053] The locally thickened protrusion is located on the outside of the stator cone wall and is integrally formed with the stator cone wall. Each aerodynamic jet structure is provided with an independent locally thickened protrusion. The locally thickened protrusions are spaced apart from each other in the circumferential direction. The two sides of the locally thickened protrusions along the meridional direction of the stator cone wall are connected to the basic wall thickness area of ​​the stator cone wall through smooth transition contours.

[0054] The aforementioned locally thickened structure provides sufficient structural space for the spatial tilting arrangement of the aerodynamic jet structure and the machining of the tapered flow channel, ensuring that the inlet section, outlet section, and intermediate tapered surface of the aerodynamic channel can be completely arranged inside the stator cone wall. On the other hand, it avoids affecting the structural strength due to excessively small local wall thickness after machining of the aerodynamic channel. The circumferential width and meridional length of the locally thickened boss are not fixed and can be determined according to the inlet diameter, outlet diameter, channel tilt angle, and machining allowance of the aerodynamic jet structure. However, it should be ensured that the aerodynamic jet structure can be completely arranged within the locally thickened structure, and that the minimum local wall thickness at each position of the aerodynamic channel meets the structural strength requirements.

[0055] The pneumatic orifice jet structure is directly machined into the interior of the locally thickened boss of the stator cone wall, forming an integral structure with the stator cone wall. The term "directly machined" means that the pneumatic orifice jet structure is not installed on the stator cone wall through independent nozzle inserts, but is directly formed on the base material of the stator cone wall through mechanical processing. The integrated structure design avoids the assembly gaps, sealing problems, and additional parts caused by setting independent nozzle inserts. It also eliminates the risk of loosening or falling off of inserts under high temperature and high pressure environments, thus improving the reliability and durability of the structure.

[0056] In the integrated structure, the base wall thickness area and the locally thickened boss area of ​​the stator cone wall are made of the same material, with the same coefficient of thermal expansion and mechanical properties. This avoids the thermal mismatch problem that may occur when connecting dissimilar materials. At the same time, the integrated structure eliminates the assembly interface between the nozzle and the cone wall, reduces potential leakage paths, and helps to improve the sealing and reliability of the cooling air supply.

[0057] In some embodiments, such as Figure 4 As shown, the inlet diameter of the pneumatic channel is d 1. The outlet diameter is d 2, and d 1 greater than d 2. To ensure that the aerodynamic channel maintains a tapered configuration along the airflow direction, a first control length is set along the central axis of the aerodynamic jet structure. l 1 and second control length l2, used to define the relative positions of the inlet section, the outlet section, and the tapered surface located between the inlet and outlet sections; wherein, the first control length l 1 represents the distance from the start position to the end position of the tapered section, and the second control length. l 2. Characterizes the distance from the starting position of the convergent section to the outlet section, through the inlet diameter. d 1. Outlet diameter d 2. First control length l 1 and second control length l The combined control of 2 can limit the degree of contraction of the tapered surface inside the aerodynamic channel and the length of the channel, so that the airflow can achieve smooth and sufficient acceleration as it flows toward the outlet.

[0058] Furthermore, the profile of the pneumatic channel forms a control angle in its tapering section. i 3. Control the included angle i 3 is the angle between the generatrix of the tapered section of the aerodynamic channel and the central axis of the aerodynamic jet structure. This angle, in conjunction with the inlet diameter, outlet diameter, and flow channel control length, is used to define the surface arrangement near the inlet and tapered section of the aerodynamic channel, so that the aerodynamic channel can transition continuously and smoothly from the inlet to the outlet in the locally thickened area.

[0059] Specifically, such as Figure 4 and Figure 6 As shown, the inlet diameter of the pneumatic channel d 1 is 5.4mm, outlet diameter d 2 is 2.7mm, and the ratio of inlet diameter to outlet diameter is 2:1. This contraction ratio ensures sufficient acceleration of the cooling airflow while avoiding excessive flow loss due to excessive contraction. The first control length is set along the central axis of the aerodynamic jet structure. l 1 is 4.4mm, the second control length l 2 is 7.0mm, controlling the included angle. i With 30°, the above parameter combination forms a flow channel configuration that is continuously and smoothly tapered from an inlet diameter of 5.4 mm to an outlet diameter of 2.7 mm. The airflow can be smoothly accelerated within it and reach the highest velocity at the outlet throat. Numerical calculations have verified that the aerodynamic jet structure with the above parameter combination has excellent flow coefficient and pre-swirl efficiency.

[0060] In other embodiments, the inlet diameter d 1. Outlet diameter d 2. First control length l 1. Second control length l 2 and control the included angle i3. Adjustments can be made according to the required air supply flow rate and nozzle pressure ratio, but the pneumatic channel should maintain a continuous gradual narrowing from the inlet to the outlet, and the outlet should be the minimum cross-section of the flow channel; for example, in applications requiring a larger air supply flow rate, the inlet diameter can be appropriately increased. d 1 and outlet diameter d 2. In applications requiring higher exit speeds, the contraction ratio can be appropriately increased or the control angle adjusted. i 3. However, regardless of how the parameters change, the interior of the pneumatic channel should maintain a surface feature that is continuously tapered and smoothly transitions from the inlet to the outlet to ensure the stability and efficiency of the internal flow.

[0061] In some embodiments, such as Figure 3 As shown, the basic wall thickness of the stator cone wall w 1 represents 2mm. The basic wall thickness refers to the basic wall thickness of the area on the stator cone wall without locally thickened bosses. This wall thickness meets the structural strength requirements of the stator cone wall under normal operating conditions. The total thickness at the locally thickened bosses... w The thickness is 6.6mm, which means that on the basis of a base wall thickness of 2mm, the height of the locally thickened boss protruding outward is 4.6mm. This total thickness can provide sufficient processing space for the inclined arrangement of the pneumatic orifice jet structure and the gradually narrowing flow channel.

[0062] The locally thickened bosses are connected to the basic wall thickness region of the stator cone wall on both sides along the meridional direction through smooth transition profiles. The radii of curvature of the two transition profiles are respectively... r 1 and r 2， The transition profile adopts a smooth curved surface design, which can avoid stress concentration caused by abrupt changes in wall thickness and ensure the structural strength at the connection between the locally thickened boss and the base wall thickness area. By adjusting the radius of curvature of the transition profile, the stress distribution at the connection between the locally thickened boss and the base wall thickness area of ​​the stator cone wall can be optimized, further improving the structural strength.

[0063] In some embodiments, such as Figure 3 and Figure 5 As shown, in order to clarify the spatial orientation of the aerodynamic orifice jet structure, a local geometric reference is established at the location of the jet structure; where A represents the local normal of the stator cone wall at the curvature position of the jet structure, B represents the central axis of the aerodynamic orifice jet structure, and C represents the local tangent of the stator cone wall at the curvature position and located in the corresponding normal section.

[0064] Within the meridional section of the stator cone wall, the angle between the projection of the central axis of the aerodynamic jet structure and the tangent of the stator cone wall at that point is . i 1, i1 is 90°, meaning that the projection of the central axis of the aerodynamic jet structure in the meridional direction is basically perpendicular to the tangent of the stator cone wall at that point. In other words, the central axis of the jet structure is arranged basically along the normal of the stator cone wall in the meridional direction. Through the above setting, unnecessary deflection of the cooling airflow in the meridional direction can be avoided, ensuring that the airflow enters the rear journal cone wall cavity in the expected direction.

[0065] Within the normal section of the stator cone wall, the angle between the central axis B of the aerodynamic jet structure and the tangent C of the stator cone wall at that point is . i 2, i 2 is 20°, meaning the pre-swirl angle is 20°. The angle between the central axis B of the aerodynamic jet structure and the normal A of the stator cone wall at that point is... α , α =90° - i 2， α With an angle of 70°, the outlet airflow of the aerodynamic jet structure, when injected into the rear journal cone wall cavity, possesses not only a radial velocity component towards the interior of the rear journal cone wall cavity but also a circumferential velocity component along the circumference of the rotor cone wall. The direction of this circumferential velocity component is the same as the rotor's rotation direction, thereby allowing the cooling airflow entering the rear journal cone wall cavity to undergo pre-swirl. The pre-swirl angle... i The value of 2 directly affects the magnitude of the circumferential velocity component obtained by the cooling airflow, and thus affects the pre-swirl effect and pre-swirl angle. i When 2 is 20°, it can ensure that the cooling airflow obtains sufficient circumferential velocity while avoiding the radial flow of the airflow being affected by excessive circumferential velocity.

[0066] Pre-rotation angle i 2. Adjustments can be made based on the rotational speed of the rotor cone wall, the required rotational ratio, and the geometry of the rear journal cone wall cavity; for example, in applications with lower rotor speeds, the pre-rotation angle can be appropriately increased. i 2. To avoid the circumferential velocity of the cooling airflow exceeding the circumferential velocity of the rotor cone wall, which would cause reverse shearing; in applications with higher rotor speeds, the pre-swirl angle can be appropriately reduced. i 2. To increase the circumferential velocity component of the cooling airflow and improve the pre-swirl effect.

[0067] In some embodiments, multiple aerodynamic orifice jet structures are arranged in a single row uniformly along the same circumferential position of the stator cone wall. The term "same circumferential position" means that each aerodynamic orifice jet structure is located at the same radial position in the meridional direction of the stator cone wall, that is, each jet structure is arranged on the same circumference. The term "single row arrangement" means that each aerodynamic orifice jet structure is set in only one row in the meridional direction of the stator cone wall, and multiple rows of jet structures are not set in different radial positions. The single row arrangement is beneficial to simplify the structure, reduce the occupation of the flow channel, and facilitate processing and manufacturing.

[0068] All aerodynamic jet structures have the same orifice size, spatial tilt angle, and outlet airflow direction; in other words, the inlet diameter of each jet structure is the same. d 1. Outlet diameter d 2. First control length l 1. Second control length l 2. Control the included angle i 3. Meridian direction angle i 1. Pre-rotation angle i 2. Pre-rotation space angle α All parameters are the same, and the circumferential velocity component of the airflow at the outlet of each jet structure is in the same direction as the rotor rotation direction.

[0069] By using the same orifice parameters and spatial angle arrangement, it can be ensured that the cooling airflow at the outlet of each jet structure forms a uniform pre-swirling flow field in the rear axle journal cone wall cavity, avoiding uneven flow field and local overheating caused by inconsistent performance of each jet structure.

[0070] The number of aerodynamic orifice jet structures is N The circumferential periodic angle between two adjacent aerodynamic jet structures is β ,and β =360° / N， That is, each aerodynamic jet structure is evenly distributed at equal intervals along the circumference of the stator cone wall. The uniform circumferential arrangement is conducive to the formation of an axisymmetric flow field in the rear axle journal cone wall cavity of the cooling airflow, avoiding the generation of local eddies or flow dead zones due to non-uniform arrangement, thereby ensuring the uniformity of the circumferential cooling effect.

[0071] Specifically, the number of aerodynamic orifice jet structures N There are 12, and the circumferential periodic angle between two adjacent aerodynamic jet structures is... β With an angle of 30°, 12 aerodynamic jet structures are evenly distributed at equal intervals along the circumference of the stator cone wall. Each jet structure has the same channel size, spatial tilt angle, and outlet airflow direction. The total flow area of ​​the 12 jet structures can meet the cooling air supply flow requirements of the rear axle journal cone wall cavity and its downstream components. At the same time, the circumferentially uniform arrangement of the 12 jet structures can form a good axisymmetric pre-swirling flow field in the rear axle journal cone wall cavity, avoiding circumferentially uneven cooling effect.

[0072] The number of jet structures can be determined based on the circumferential dimensions of the rear axle journal cone wall cavity, the required air flow rate, and the actual machining method. For example, in applications with high air flow rate requirements, 16 jet structures can be used, where the circumferential period angle between adjacent jet structures is... βThe angle is 22.5°. The inlet and outlet diameters of each jet structure can be reduced accordingly to maintain the total flow area. In applications with lower gas flow requirements, eight jet structures can be used, in which case the circumferential periodic angle between adjacent jet structures is... β The angle is 45°, and the inlet and outlet diameters of each jet structure can be increased accordingly to ensure the total gas supply flow rate.

[0073] In some embodiments, when the engine is operating, the cooling airflow in the air supply chamber outside the stator cone wall first enters the inlet of the aerodynamic jet structure. Because the internal aerodynamic channels of the aerodynamic jet structure continuously narrow from the inlet to the outlet, the cooling airflow gradually accelerates as it flows through the channels. At the inlet section of the aerodynamic channel, the airflow velocity is low and the static pressure is high. As the flow cross-sectional area continuously decreases along the airflow direction, the airflow velocity gradually increases and the static pressure gradually decreases. At the outlet section of the aerodynamic channel, the airflow velocity reaches its maximum and the static pressure drops to its minimum. Because the aerodynamic channel uses a smooth, arc-shaped surface transition, the airflow does not experience significant flow separation during acceleration, resulting in minimal flow loss. The cooling airflow is then injected at high speed into the rear journal cone wall cavity from the outlet throat.

[0074] Meanwhile, since the central axis of the aerodynamic orifice jet structure is arranged at an inclination relative to the stator cone wall, the outlet airflow of the aerodynamic orifice jet structure, when injected into the rear journal cone wall cavity, not only has a velocity component toward the interior of the rear journal cone wall cavity, but also a circumferential velocity component along the circumference of the rotor cone wall. Moreover, the direction of this circumferential velocity component is consistent with the rotation direction of the rotor cone wall. Therefore, the cooling airflow entering the rear journal cone wall cavity has a high rotational ratio.

[0075] Compared to the traditional simple straight-hole throttling scheme, the pneumatic orifice jet structure of this embodiment can significantly reduce the relative circumferential velocity between the cooling airflow and the rotor cone wall. When the circumferential velocity of the cooling airflow matches the circumferential velocity of the rotor cone wall, the shearing effect between the airflow and the rotor wall is greatly reduced, and the resulting frictional temperature rise is also reduced accordingly. At the same time, the relative total temperature of the cooling airflow is kept at a low level, which is beneficial to improving the cooling effect of the rear journal cone wall cavity and its downstream components.

[0076] The cooling airflow injected into the rear journal cone wall cavity by the pneumatic orifice jet structure continues to flow radially inward along the rear journal cone wall cavity, cooling the rotor cone wall along the flow. Subsequently, the cooling airflow continues to flow downstream, passing through the CDP grate element and the drum cavity in sequence, providing cooling airflow for these downstream components. Since the cooling airflow has already obtained pre-swirl in the same direction as the rotor rotation when it enters the rear journal cone wall cavity, its relative total temperature is relatively low. Therefore, it still has strong cooling capacity when flowing through downstream components, which can effectively reduce the wall temperature of downstream components.

[0077] Working principle: When the engine is running, the cooling airflow outside the stator cone wall first enters the aerodynamic orifice jet structure. As the jet structure flow channel gradually narrows from the inlet to the outlet, the cooling airflow gradually accelerates within the flow channel and is injected into the cone wall cavity from the outlet throat. At the same time, since the central axis of the jet structure is inclined relative to the stator cone wall, the outlet airflow has a circumferential velocity component in the same direction as the rotor rotation, giving the cooling airflow entering the cone wall cavity a higher rotation ratio. Compared with a simple straight orifice without pre-swirl, the aerodynamic orifice jet structure provided in some embodiments of this application can reduce the relative circumferential velocity between the cooling airflow and the rotor cone wall, and reduce the shearing effect and frictional temperature rise between the airflow and the rotor wall. Meanwhile, the continuously narrowing and smoothly transitioning aerodynamic flow channel can reduce flow separation inside the jet structure, improve the flow coefficient and pre-swirl efficiency of the jet structure. The cooling airflow injected into the cone wall cavity by the jet structure continues to flow radially inward and downstream after cooling the rotor cone wall, and sequentially cools and supplies air to downstream components.

[0078] Corresponding to the aforementioned embodiments of the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, this application also provides an embodiment of a design method for an aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply.

[0079] In one exemplary embodiment, such as Figure 8 As shown, the design method of the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply may include the following steps: S1: Obtain the structural parameters and operating conditions of the rear journal conical wall cavity of the aero-engine to be designed. The structural parameters include the spatial structure of the stator conical wall and the rotor conical wall, the flow channel size of the conical wall cavity, and the rotor speed. The operating conditions include the cooling gas requirements of the conical wall cavity, the supply pressure, the supply temperature, the pressure boundary, and the cooling requirements of downstream components. Based on the structural parameters and operating conditions, determine the cooling gas flow rate and pre-swirl degree that the aerodynamic orifice jet structure needs to meet. S2: Determine the number N of jet structures based on the spatial structure of the stator cone wall and the required cold air flow rate of the aerodynamic orifice jet structure, and arrange multiple aerodynamic orifice jet structures circumferentially along the stator cone wall. S3: Based on the spatial structure of the stator cone wall and the spatial arrangement requirements of the jet channel, an independent locally thickened protrusion is established at the corresponding position of each jet structure. The locally thickened protrusion is set on the gas supply side of the stator cone wall and forms an integral structure with the stator cone wall. The circumferential width, meridional length and transition profile of the locally thickened protrusion are determined according to the jet structure inlet diameter, jet structure spatial inclination angle, channel length and processing requirements, and the minimum remaining wall thickness around the jet structure channel is ensured to meet the strength requirements. S4: Determine the inlet diameter based on the required cooling air flow rate and system pressure ratio of the aerodynamic jet structure. d1 and outlet throat diameter d 2. A circular pneumatic channel with a continuous tapering from the inlet to the outlet is constructed, wherein the inlet cross section and the outlet cross section are both radial cross sections of the pneumatic channel, and the outlet cross section serves as the minimum flow cross section of the flow channel. The system pressure ratio is determined based on the gas supply pressure and pressure boundary of the conical wall cavity. S5: Based on inlet diameter d 1. Outlet diameter d 2. The total length of the tapered flow channel is determined by the meridional length of the locally thickened protrusion, and a first control length is set along the central axis of the jet structure. l 1 and second control length l 2. This defines the relative positions of the inlet cross-section, outlet cross-section, and intermediate tapering surface, causing the flow channel cross-sectional area to continuously decrease along the direction of the cold air. A smooth transition is achieved between the inlet and outlet cross-sections using a circular arc surface. The first control length is determined based on the flow coefficient, internal flow separation, and manufacturing feasibility. l 1 and second control length l The specific value of 2, the first control length l 1 represents the distance from the start position to the end position of the tapered section, and the second control length. l 2 represents the distance from the starting position of the contraction section to the outlet section; the total length of the contraction channel is... l 1. And the total length does not exceed the meridional length of the locally thickened boss; S6: Establish a spatial orientation reference based on the local normal, centerline, and local tangent of the stator cone wall at the location of the jet structure; determine the spatial attitude of the centerline based on the target pre-spin direction; and determine the angle within the meridional section of the stator cone wall. i 1. Determine the angle within the normal section of the stator cone wall. i 2, and according to α =90° - i 2. Determine the pre-swirl space angle of the jet structure α This causes the outlet airflow to jet into the conical cavity and obtain a circumferential velocity component that is consistent with the rotor's rotation direction. S7: Establish a three-dimensional flow calculation model by combining the designed aerodynamic orifice jet structure with the stator cone wall, rotor cone wall, wheel rim and downstream components. Set the inlet pressure, temperature, cone wall cavity pressure boundary, rotor speed and flow boundary at wheel rim and drum cavity of the jet structure according to the actual engine working state, and perform aerodynamic performance calculation on the designed jet structure. S8: Evaluate the flow coefficient, pre-swirl efficiency, outlet flow direction, cold air rotation state in the cone wall cavity, relative velocity near the rotor cone wall, and cold air temperature rise index of the jet structure based on the aerodynamic performance calculation results. When all performance indicators meet the design requirements, determine the current structure as the target aerodynamic orifice jet structure. When any performance indicator fails to meet the design requirements, determine the corresponding adjustment parameters and return steps according to the type of the unmet indicator, and perform iterative correction.

[0080] In some embodiments, such as Figure 8 As shown, the specific implementation process of the design method for the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply is as follows: S1: Determine the cooling requirements and design boundaries of the rear axle journal cone wall cavity.

[0081] Obtain the structural parameters and operating conditions of the rear journal conical wall cavity of the aero-engine to be designed. The structural parameters include the spatial structure of the stator conical wall and the rotor conical wall, the flow channel size of the conical wall cavity, and the rotor speed. The operating conditions include the cooling gas requirements of the conical wall cavity, the supply pressure, the supply temperature, the pressure boundary, and the cooling requirements of downstream components. Based on the above structural parameters and operating conditions, determine the cooling gas flow rate and pre-swirl degree that the aerodynamic orifice jet structure needs to meet.

[0082] Specifically, the supply pressure is the total air pressure in the compressor stage bleed chamber, and the pressure boundary is the static pressure distribution in the cone wall cavity. The two together constitute the working pressure ratio of the jet structure. The cooling air demand is determined according to the cooling flow requirements of the downstream CDP grate element and the drum cavity. The pre-swirl degree is determined according to the rotor speed. The higher the rotor speed, the greater the required rotation ratio, in order to match the circumferential speed of the rotor cone wall and reduce the relative speed.

[0083] S2: Determine the circumferential arrangement of the jet structure.

[0084] Based on the obtained stator cone wall spatial structure and the required cooling gas flow rate of the determined aerodynamic orifice jet structure, the number N of jet structures is determined, and multiple aerodynamic orifice jet structures are arranged circumferentially along the stator cone wall. The multiple jet structures are arranged in a single row with equal intervals, and adjacent jet structures form a periodic circumferential angle. β =360° / N .

[0085] In this embodiment, N =12, β =30°, the total flow area of ​​the 12 jet structures meets the cooling air supply flow requirements of the conical wall cavity and its downstream components. In other embodiments... N The timeframe can be selected between 6 and 24 depending on the specific working conditions.

[0086] S3: Establish a locally thickened structure for the jet structure.

[0087] Based on the obtained spatial structure of the stator cone wall and the spatial arrangement requirements of the jet channels, an independent locally thickened protrusion is established at the corresponding position of each jet structure. The locally thickened protrusion is set on the gas supply side of the stator cone wall and forms an integral structure with the stator cone wall.

[0088] The circumferential width, meridional length, and transition profile of the locally thickened boss are determined based on the jet structure inlet diameter, jet structure spatial inclination angle, duct length, and processing requirements. Specifically, the stator cone wall base wall thickness... w 1 is 2mm, with the total thickness of the boss area being locally thickened. w 2 is 6.6mm, and the radii of curvature of the transition profile on both sides of the boss along the meridional direction are respectively r 1 is 4.2 mm and r 2 is 4.6 mm. At the same time, ensure that the minimum remaining wall thickness around the jet structure channel is not less than 2 mm to meet the structural strength requirements. The above dimensional parameters can be adjusted within a certain range, but it should be ensured that the jet structure channel can be completely arranged in the locally thickened boss, and the minimum local wall thickness at each position meets the strength requirements.

[0089] S4: Determine the inlet and outlet dimensions of the jet structure channel.

[0090] Determine the inlet diameter based on the determined cold air flow rate and system pressure ratio. d 1 and outlet diameter d 2. The system pressure ratio is determined based on the gas supply pressure and the cone wall cavity pressure boundary obtained in step one. This pressure ratio determines the driving pressure difference between the inlet and outlet of the jet structure. The inlet section and the outlet section are both radial sections of the pneumatic channel, and the outlet section serves as the minimum flow section of the flow channel.

[0091] A circular pneumatic channel is constructed that gradually narrows from the inlet to the outlet. In this embodiment, the inlet diameter is... d 1 is 5.4mm, and the diameter of the outlet throat is... d 2 is 2.7mm, shrinkage ratio d 1 / d In other embodiments, the shrinkage ratio can be adjusted from 1.8 to 2.2.

[0092] S5: Construct a gradually narrowing flow channel for the jet structure.

[0093] According to the inlet diameter d 1. Outlet diameter d 2. The total length of the tapering channel is determined by defining the meridional length of the locally thickened protrusion. A first control length is set along the central axis of the jet structure. l 1 and second control length l2. This defines the relative positions of the inlet cross-section, outlet cross-section, and intermediate tapering surface, causing the flow channel cross-sectional area to continuously decrease along the direction of the cold air. A smooth transition is achieved between the inlet and outlet cross-sections using a circular arc surface. The first control length is determined based on the flow coefficient, internal flow separation, and manufacturing feasibility. l 1 and second control length l The specific value of 2.

[0094] First control length l 1 represents the distance from the start position to the end position of the tapered section, and the second control length. l 2 represents the distance from the starting position of the contraction section to the outlet section; the total length of the contraction channel is... l 1. And the total length does not exceed the meridional length of the locally thickened boss.

[0095] In this embodiment, the first control length l 1 is 4.4mm, the second control length l 2 is 7.0mm, controlling the included angle. i 3 = 30° i 3 represents the angle between the generatrix of the tapered section of the aerodynamic channel and the central axis of the jet structure, determined by the inlet diameter. d 1. Outlet diameter d 2 and the second control length l 2. To be jointly determined and meet the requirements. .

[0096] S6: Determine the installation angle of the jet structure space.

[0097] A spatial orientation reference is established using the local normal A, centerline B, and local tangent C of the stator cone wall at the location of the jet structure. The spatial attitude of the centerline is determined based on the target pre-spin direction, and the angle is determined within the meridional section of the stator cone wall. i 1. Determine the angle within the normal section of the stator cone wall. i 2, and according to α =90° - i 2. Determine the pre-swirl space angle of the jet structure α This causes the outlet airflow to jet into the conical cavity and obtain a circumferential velocity component that is consistent with the rotor's rotation direction.

[0098] In this embodiment, i 1 = 90° i 2=20° α =70°, where, i 1=90° ensures that the central axis of the jet structure is arranged along the normal direction of the stator cone wall in the meridional direction, avoiding unnecessary radial deflection of the airflow. i 2=20° ensures that the outlet airflow obtains the optimal circumferential velocity component that matches the rotor's rotation direction.α and i 2. They are complementary and together define the spatial orientation of the jet structure, such as Figure 9 As shown, Figure 9 (a) is a simple straight hole scheme. Figure 9 (b) The aerodynamic orifice jet structure provided in this application adopts a pre-swirl angle. i After the structural design of 2=20°, the rotation ratio of the jet structure outlet airflow is around 1, which matches well with the rotor cone wall.

[0099] In other embodiments, the pre-rotation angle i 2. The pre-rotation angle can be adjusted according to the rotational speed of the rotor cone wall, the required rotation ratio, and the geometry of the cone wall cavity; specifically, the pre-rotation angle... i The value of 2 satisfies: ; in, For the desired rotation ratio, Let be the circumferential linear velocity of the rotor cone wall at the radius of the jet structure outlet. , The rotor angular velocity, Let be the radius of the location at the center of the exit section of the jet structure. The resultant velocity of the airflow at the exit of the jet structure. The value range is 0.7≤ ≤1.1.

[0100] when > When, reduce the pre-rotation angle i 2. To increase the circumferential velocity component of the airflow, when < At that time, increase the pre-rotation angle i 2. To reduce the circumferential velocity component of the airflow, so that the circumferential velocity component of the outlet airflow approaches... .

[0101] Pre-rotation angle i The constraint range of 2 is 10°≤ i 2≤30°, and i 2 and pre-spin space angle α satisfy α =90° - i 2.

[0102] when At this time, the circumferential velocity component of the outlet airflow is equal to the circumferential linear velocity of the rotor cone wall, and the relative circumferential velocity between the cooling airflow and the rotor cone wall is zero. At this time, the wall shearing effect is minimal, and the frictional temperature rise is minimal.

[0103] To further optimize the pre-spin angle iThe value of 2 can be used to construct the optimization objective function: ; in, The resultant velocity of the airflow at the exit of the jet structure. This represents the circumferential velocity component of the outlet airflow. The circumferential linear velocity of the rotor cone wall is... This represents the total pressure loss at the inlet and outlet of the jet structure. The total pressure at the inlet of the jet structure. and These are the weighting coefficients, and These are used to adjust the weight ratios of pre-spinning matching degree and flow loss in the optimization objective, respectively. By minimizing... , within 10°≤ i The pre-rotation angle is obtained within the constraint range of 2 ≤ 30°. i The optimal value of 2.

[0104] S7: Establish a three-dimensional flow calculation model for the rear axle neck cone wall cavity.

[0105] A three-dimensional flow calculation model is established by combining the designed aerodynamic jet structure with the stator cone wall, rotor cone wall, wheel rim, and downstream components. Based on the actual engine operating conditions, the inlet pressure and temperature of the jet structure, the pressure boundary of the cone wall cavity, the rotor speed, and the flow boundaries at the wheel rim and drum cavity are set to calculate the aerodynamic performance of the designed jet structure.

[0106] Specifically, in the three-dimensional flow calculation model, the inlet boundary conditions of the jet structure are set as total pressure (supply pressure) and total temperature (supply temperature), the outlet boundary conditions are set as static pressure (pressure boundary of the cone wall cavity), the rotor cone wall is set as a rotating wall boundary (rotor speed is rotor speed), and corresponding flow boundaries (such as mass flow outlet or pressure outlet) are set at the rim and drum cavity. The Navier-Stokes equations are solved using computational fluid dynamics methods to obtain the flow field information inside the jet structure and the cone wall cavity.

[0107] S8: Evaluate the jet structure design results and iteratively optimize them.

[0108] The following performance indicators of the jet structure are evaluated based on the aerodynamic performance calculation results: flow coefficient, pre-swirl efficiency, outlet flow direction, cold air rotation state in the cone wall cavity, relative velocity near the rotor cone wall, and cold air temperature rise along the path. When all performance indicators meet the design requirements, the current structure is determined as the target aerodynamic orifice jet structure, and the design is completed.

[0109] When performance indicators fail to meet design requirements, determine the corresponding parameters to be adjusted and the return steps based on the type of non-compliant indicator, and perform iterative correction: If the flow coefficient is lower than the design requirement, it indicates that the flow loss inside the jet structure is too large. Return to step S5 and adjust the first control length. l 1 or second control length l 2. To reduce the degree of internal flow separation by changing the shrinkage rate and flow channel length of the tapered surface; after adjustment, repeat steps S7 and S8.

[0110] If the pre-swirl efficiency is lower than the design requirement, it indicates that the circumferential velocity component of the outlet airflow is insufficient or does not match the rotor speed. Return to step S6 and adjust the pre-swirl angle. i 2. Pre-rotation space angle α or meridian angle i 1. Change the velocity vector direction of the outlet airflow; after adjustment, repeat steps S7 and S8.

[0111] If the outlet flow direction deviates from the target direction, it indicates that the spatial attitude of the jet structure does not match the geometric configuration of the cone wall cavity. Return to step S6, redetermine the spatial attitude of the centerline, and then re-execute steps S7 and S8 after adjustment.

[0112] If the rotation state of the cold air in the cone wall cavity or the relative velocity near the rotor cone wall does not meet the standard, it indicates that the pre-rotation degree of the cold air is not matched with the rotor speed. Return to step S4 and / or step S6 to adjust the inlet diameter. d 1. Outlet diameter d 2. To change the outlet airflow velocity and / or adjust the pre-swirl angle i 2. Change the circumferential velocity component of the outlet airflow, and then re-execute steps S5, S7, and S8.

[0113] If the temperature rise along the cooling air path exceeds the design requirements, it indicates that the shearing force between the cooling airflow and the rotor cone wall is too great, resulting in excessive frictional temperature rise. Return to step S6 and reduce the pre-rotation angle. i 2. Increase the circumferential velocity component of the outlet airflow to make it approach the circumferential linear velocity of the rotor cone wall, reduce the relative velocity, and then repeat steps S7 and S8 after adjustment.

[0114] If the outlet flow rate of the jet structure does not meet the cooling demand, it indicates that the flow capacity of the channel is insufficient. Return to step S4 and increase the inlet diameter. d 1. Outlet diameter d 2. Increase the circulation area; after adjustment, repeat steps S5, S7 and S8.

[0115] If the adjustment amount in any of the design steps S3 to S6 reaches the structural constraint boundary value, such as the pre-rotation angle... i 2. Reaching the 30° upper limit, inlet diameter dIf the local thickened boss size limit is reached or the minimum remaining wall thickness approaches the strength limit, but all performance indicators still cannot meet the design requirements at the same time, return to step S2, increase or decrease the number of jet structures N, and repeat steps S3 to S8.

[0116] Through the above iterative optimization process, an aerodynamic orifice jet structure that meets all design requirements is finally obtained.

[0117] To verify the technical effectiveness of the pneumatic orifice jet structure of the present invention, under the same operating conditions, computational fluid dynamics numerical simulation was used to compare and verify the schemes of some embodiments of the present application with the traditional simple straight orifice scheme and the straight orifice nozzle scheme. The three schemes were numerically calculated under the same inlet total pressure, inlet total temperature, and outlet back pressure boundary conditions. The comparison results are as follows: Figure 7 As shown: Regarding the flow coefficient, the flow coefficient of the pneumatic orifice jet structure provided in some embodiments of this application is 0.897, the flow coefficient of the traditional simple straight orifice scheme is 0.664, and the flow coefficient of the straight orifice nozzle scheme is 0.713. It can be seen that, compared to the traditional simple straight orifice scheme, some embodiments of this application improve the flow coefficient by approximately 35.1%; compared to the straight orifice nozzle scheme, some embodiments of this application improve the flow coefficient by approximately 25.8%.

[0118] Regarding pre-swirl efficiency, the pre-swirl efficiency of the aerodynamic orifice jet structure provided in some embodiments of this application is 0.898, while the pre-swirl efficiency of the straight orifice nozzle scheme is 0.574. Some embodiments of this application improve the efficiency by approximately 56.4% compared to the straight orifice nozzle scheme.

[0119] In terms of cooling effect, compared with the traditional simple straight-hole throttling scheme, the pneumatic orifice jet structure provided in some embodiments of this application results in a higher rotational speed of the airflow injected into the conical wall cavity through the pneumatic orifice jet structure, a significant reduction in the relative circumferential velocity between the cooling airflow and the rotor conical wall, and a significant reduction in frictional temperature rise. This embodiment, compared with the traditional simple straight-hole scheme, as... Figure 10 As shown, Figure 10 (a) is a simple straight hole scheme. Figure 10 (b) Under the same conditions of total inlet pressure, static outlet pressure, and total inlet temperature (i.e., the same system pressure ratio and the same inlet temperature), the relative total temperature of the airflow at the outlet of the drum cavity of the pneumatic orifice jet structure provided in this application is reduced from 1184 K to 972 K, and the temperature drop level is increased by more than 200 K.

[0120] The numerical calculation verification results above show that the aerodynamic orifice jet structure of some embodiments of this application has significant advantages in terms of flow coefficient, pre-swirl efficiency, and cooling effect. The aerodynamic orifice design with continuous tapering and smooth arc transition effectively suppresses internal flow separation and improves flow capacity. By arranging the central axis of the jet structure at an inclination relative to the stator cone wall, the outlet airflow obtains a circumferential velocity component consistent with the rotor rotation direction, which significantly improves the pre-swirl efficiency. The synergistic effect of the two ensures that the cooling airflow has a high rotation ratio and a low relative total temperature when entering the cone wall cavity, thereby achieving a significant improvement in the cooling effect along the cone wall cavity and its downstream components. This application conforms to the refined low-entropy production design concept of secondary air system flow path and can be widely used in the high-efficiency cooling air supply design of advanced aero-engine air systems.

[0121] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, characterized in that, The rear axle journal conical wall cavity is formed by the stator conical wall and the rotor conical wall opposite to the stator conical wall; The pneumatic orifice jet structure is disposed on and penetrates the stator cone wall. The inlet of the pneumatic orifice jet structure is connected to the air supply chamber on the outside of the stator cone wall, and the outlet of the pneumatic orifice jet structure is connected to the rear axle journal cone wall cavity. The stator cone wall is provided with an independent locally thickened protrusion at the corresponding position of each pneumatic orifice jet structure. The locally thickened protrusion is located on the outside of the stator cone wall and is integrally formed with the stator cone wall. The locally thickened protrusion is connected to the basic wall thickness area of ​​the stator cone wall on both sides along the meridional direction of the stator cone wall through a smooth transition contour. The pneumatic jet structure has an internal pneumatic channel that gradually narrows from the inlet to the outlet. The inlet and outlet sections of the pneumatic channel are both radial sections. The outlet section is the minimum flow section of the pneumatic channel and forms the throat. The inlet and outlet sections are smoothly connected by a circular arc surface, so that the flow cross-sectional area of ​​the pneumatic channel continuously decreases along the airflow direction. The central axis of the aerodynamic orifice jet structure is arranged at an inclination relative to the stator cone wall, and the circumferential velocity direction of the outlet airflow of the aerodynamic orifice jet structure is consistent with the rotation direction of the rotor cone wall.

2. The pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 1, characterized in that, The inlet diameter of the pneumatic channel is d 1. The outlet diameter is d 2, and d 1 greater than d 2. The inlet diameter d The value of 1 ranges from 5mm to 6mm, and the outlet diameter... d The value of 2 ranges from 2.5 mm to 3.0 mm; A first control length is provided along the central axis of the aerodynamic orifice jet structure. l 1 and second control length l 2, used to define the relative positions of the inlet section, the outlet section, and the tapered surface located between the inlet section and the outlet section, the first control length l The value of 1 ranges from 4mm to 5mm, and the second control length l The value of 2 ranges from 6.5 mm to 7.5 mm; The profile of the pneumatic channel forms a control angle at its tapering section. θ 3， The control angle θ The value of 3 ranges from 20° to 40°.

3. The pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 1, characterized in that, The basic wall thickness of the stator cone wall w The value of 1 ranges from 2mm to 3mm, and the total thickness of the locally thickened boss is... w The value of 2 ranges from 6mm to 7mm, and the radius of curvature of the smooth transition contour on both sides of the locally thickened boss is... r 1 and r The value range of 2 is 4mm to 4.5mm and 4.5mm to 5.0mm respectively.

4. The pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 3, characterized in that, Within the meridional section of the stator cone wall, the angle between the projection of the central axis of the aerodynamic orifice jet structure and the tangent of the stator cone wall at that location is . θ 1, θ 1 is 90°; Within the normal cross-section of the stator cone wall, the angle between the central axis of the aerodynamic jet structure and the tangent to the stator cone wall at that point is . θ 2, θ 2 is 20°; The angle between the central axis of the aerodynamic jet structure and the normal to the stator cone wall at that location is: α , α =90° - θ 2, α It is 70°.

5. The pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 1, characterized in that, Multiple aerodynamic jet structures are arranged in a single row at the same circumferential position along the stator cone wall, and the channel size, spatial tilt angle and outlet airflow direction of each aerodynamic jet structure are the same. The number of the pneumatic orifice jet structures is N The circumferential periodic angle between two adjacent aerodynamic jet structures is β , β =360° / N .

6. A design method for an aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply, used to realize the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in any one of claims 1 to 5, characterized in that, include: S1: Obtain the structural parameters and operating conditions of the rear journal conical wall cavity of the aero-engine to be designed. The structural parameters include the spatial structure of the stator conical wall and the rotor conical wall, the flow channel size of the conical wall cavity, and the rotor speed. The operating conditions include the cooling gas requirements of the conical wall cavity, the supply pressure, the supply temperature, the pressure boundary, and the cooling requirements of downstream components. Based on the structural parameters and operating conditions, determine the cooling gas flow rate and pre-swirl degree that the aerodynamic orifice jet structure needs to meet. S2: Determine the number N of jet structures based on the spatial structure of the stator cone wall and the required cold air flow rate of the aerodynamic orifice jet structure, and arrange multiple aerodynamic orifice jet structures circumferentially along the stator cone wall. S3: Based on the spatial structure of the stator cone wall and the spatial arrangement requirements of the jet channel, an independent locally thickened protrusion is established at the corresponding position of each jet structure. The locally thickened protrusion is set on the gas supply side of the stator cone wall and forms an integral structure with the stator cone wall. The circumferential width, meridional length and transition profile of the locally thickened protrusion are determined according to the jet structure inlet diameter, jet structure spatial inclination angle, channel length and processing requirements, and the minimum remaining wall thickness around the jet structure channel is ensured to meet the strength requirements. S4: Determine the inlet diameter based on the required cooling air flow rate and system pressure ratio of the aerodynamic jet structure. d 1 and outlet throat diameter d 2. A circular pneumatic channel with a continuous tapering from the inlet to the outlet is constructed, wherein the inlet cross section and the outlet cross section are both radial cross sections of the pneumatic channel, and the outlet cross section serves as the minimum flow cross section of the flow channel. The system pressure ratio is determined based on the gas supply pressure and pressure boundary of the conical wall cavity. S5: Based on inlet diameter d 1. Outlet diameter d 2. The total length of the tapered flow channel is determined by the meridional length of the locally thickened protrusion, and a first control length is set along the central axis of the jet structure. l 1 and second control length l 2. This defines the relative positions of the inlet cross-section, outlet cross-section, and intermediate tapering surface, causing the flow channel cross-sectional area to continuously decrease along the direction of the cold air. A smooth transition is achieved between the inlet and outlet cross-sections using a circular arc surface. The first control length is determined based on the flow coefficient, internal flow separation, and manufacturing feasibility. l 1 and second control length l The specific value of 2, the first control length l 1 represents the distance from the start position to the end position of the tapered section, and the second control length. l 2 represents the distance from the starting position of the contraction section to the outlet section; the total length of the contraction channel is... l 1. And the total length does not exceed the meridional length of the locally thickened boss; S6: Establish a spatial orientation reference based on the local normal, centerline, and local tangent of the stator cone wall at the location of the jet structure; determine the spatial attitude of the centerline based on the target pre-spin direction; and determine the angle within the meridional section of the stator cone wall. θ 1. Determine the angle within the normal section of the stator cone wall. θ 2, and according to α =90° - θ 2. Determine the pre-swirl space angle of the jet structure α This causes the outlet airflow to jet towards the inside of the cone wall cavity and obtain a circumferential velocity component consistent with the rotor's rotation direction. S7: Establish a three-dimensional flow calculation model by combining the designed aerodynamic orifice jet structure with the stator cone wall, rotor cone wall, wheel rim and downstream components. Set the inlet pressure, temperature, cone wall cavity pressure boundary, rotor speed and flow boundary at wheel rim and drum cavity of the jet structure according to the actual engine working state, and perform aerodynamic performance calculation on the designed jet structure. S8: Evaluate the flow coefficient, pre-swirl efficiency, outlet flow direction, cold air rotation state in the cone wall cavity, relative velocity near the rotor cone wall, and cold air temperature rise index of the jet structure based on the aerodynamic performance calculation results. When all performance indicators meet the design requirements, determine the current structure as the target aerodynamic orifice jet structure. When any performance indicator fails to meet the design requirements, determine the corresponding adjustment parameters and return steps according to the type of the unmet indicator, and perform iterative correction.

7. The design method of the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 6, characterized in that, When any performance indicator fails to meet the design requirements, the corresponding parameters to be adjusted and the return steps are determined based on the type of the non-compliant indicator, and iterative correction is performed, specifically including: If the flow coefficient is lower than the design requirement, return to step S5 and adjust the first control length. l 1 or second control length l 2. After adjustment, re-execute S7 and S8; If the pre-spinning efficiency is lower than the design requirement, return to step S6 and adjust the pre-spinning angle. θ 2. Pre-rotation space angle α or meridian angle θ 1. After adjustment, re-execute S7 and S8; If the outlet flow direction deviates from the target direction, return to S6, redetermine the spatial attitude of the centerline, and re-execute S7 and S8 after adjustment; If the rotation state of the cold air in the cone wall cavity or the relative velocity near the rotor cone wall does not meet the standard, return to S4 and / or S6 to adjust the inlet diameter. d 1. Outlet diameter d 2 and / or pre-rotation angle θ 2. After adjustment, re-execute S5, S7, and S8; If the temperature rise of the cold air along the path exceeds the design requirement, return to S6 and reduce the pre-swirl angle. θ 2. After adjustment, re-execute S7 and S8; If the outlet flow rate of the jet structure does not meet the cooling demand, return to S7 and increase the inlet diameter. d 1 and outlet diameter d 2. After adjustment, re-execute S5, S7, and S8; If the adjustment amount in any step from S3 to S6 reaches the structural constraint boundary value and still cannot make all performance indicators meet the design requirements at the same time, return to S2, increase or decrease the number of jet structures N, and re-execute S3 to S8.

8. The design method of the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 6, characterized in that, In step S6, the pre-rotation angle is determined based on the rotational speed of the rotor cone wall and the required rotation ratio. θ 2. Expressed by the formula: ； in, β For the desired rotation ratio, Let be the circumferential linear velocity of the rotor cone wall at the radius of the jet structure outlet. , The rotor angular velocity, Let be the radius of the location at the center of the exit section of the jet structure. The resultant velocity of the airflow at the exit of the jet structure. β The value range is 0.7≤ β ≤1.1; when > When, reduce the pre-rotation angle θ 2. To increase the circumferential velocity component of the airflow, when < At that time, increase the pre-rotation angle θ 2. To reduce the circumferential velocity component of the airflow, so that the circumferential velocity component of the outlet airflow approaches... ; Pre-rotation angle θ The constraint range of 2 is 10°≤ θ 2≤30°, and θ 2 and pre-spin space angle α satisfy α =90° - θ 2; when At that time, the circumferential velocity component of the outlet airflow is equal to the circumferential linear velocity of the rotor cone wall, and the relative circumferential velocity between the cooling airflow and the rotor cone wall is zero.

9. The design method of the aerodynamic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 8, characterized in that, The pre-rotation angle θ The optimal value of 2 is determined by the following optimization function: ； Among them, the objective function is optimized. for: ； in, The resultant velocity of the airflow at the exit of the jet structure. This represents the circumferential velocity component of the outlet airflow. The circumferential linear velocity of the rotor cone wall is... This represents the total pressure loss at the inlet and outlet of the jet structure. The total pressure at the inlet of the jet structure. and These are the weighting coefficients, and These are used to adjust the weight ratio of pre-spin matching degree and flow loss in the optimization objective, respectively; when When the first term of the objective function is minimized, the circumferential velocity component of the outlet airflow approaches the circumferential linear velocity of the rotor cone wall. At this time, the relative circumferential velocity between the cooling airflow and the rotor cone wall approaches zero, the wall shearing effect is minimized, and the frictional temperature rise is minimized.

10. The design method of the pneumatic orifice jet structure based on rear axle journal cone wall cavity cooling air supply as described in claim 9, characterized in that, In step S3, the minimum remaining wall thickness around the jet structure channel is not less than 2 mm.

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