An adjustable pre-swirl nozzle structure for an aeroengine and a method of controlling the same

Abstract

This invention relates to the field of aero-engine cooling technology, and discloses an adjustable pre-swirl nozzle structure and its control method for aero-engines. The adjustable pre-swirl nozzle assembly and a fixed pre-swirl nozzle assembly are evenly distributed circumferentially within the pre-swirl nozzle cooling gas channel between the inner and outer casings. The axial position of the first pre-swirl nozzle blade of the adjustable pre-swirl nozzle assembly can be flexibly adjusted based on the flow test results of the adjustable pre-swirl nozzle, thereby adjusting the flow area of ​​the pre-swirl nozzle to achieve precise control of the pre-swirl nozzle flow rate. This effectively solves the problem of pre-swirl nozzle adjustment during flow test inspection, ensuring that the test flow rate value is qualified and meets design requirements. It also ensures that the adjustment degree within the same adjustable pre-swirl nozzle assembly is the same, guaranteeing a uniform temperature distribution and consistent cooling effect of the cooling air flowing out of the pre-swirl nozzle cooling gas channel, and avoiding the hazards of thermal stress caused by concentrated cooling of turbine components.

Description

Technical Field

[0001] This invention relates to the field of aero-engine cooling technology, and discloses an adjustable pre-swirl nozzle structure for aero-engines and its control method. Background Technology

[0002] As an important component of the pre-swirl air supply system in a gas turbine engine, the pre-swirl nozzle's main function is to reduce the relative total temperature of the airflow entering the turbine rotor blades. The main principle of pre-swirl cooling is to accelerate the airflow through the pre-swirl nozzle and create a larger circumferential component, thereby reducing the static temperature of the airflow and its relative velocity with the turbine rotor, thus achieving the goal of reducing the relative total temperature of the airflow.

[0003] Currently, blade-type pre-swirl nozzles have been widely used in aero-engines due to their excellent aerodynamic performance. However, because pre-swirl nozzles are generally small in size, manufacturing blade-type pre-swirl nozzles is difficult, and ensuring blade profile accuracy is challenging. The airflow capacity and outlet airflow parameters of the pre-swirl nozzle are crucial to the cooling efficiency of turbine components, directly affecting their safe operation and service life. Therefore, flow tests are typically conducted on pre-swirl nozzles under laboratory conditions before installation. Only after the flow adjustment is qualified can the nozzle meet the necessary conditions for use in aero-engines. Pre-swirl nozzles that fail the flow test are usually difficult to repair; especially in cases where the throat area is significantly larger than expected, leading to excessive flow, they are usually scrapped, resulting in significant economic losses and high time costs. Furthermore, conventional pre-swirl nozzle flow tests can only check whether the air supply flow meets design requirements; they do not consider the quality of the outlet airflow and pre-swirl performance, and cannot support an accurate assessment of the pre-swirl performance of the entire engine's pre-swirl air supply system.

[0004] In conclusion, it is crucial to incorporate measures for adjusting the flow rate and pre-swirl performance of pre-swirl nozzles during the design of air system pre-swirl nozzles. Therefore, developing and innovating precise control structures and methods for pre-swirl nozzle flow rate and pre-swirl performance are essential measures to ensure the stable operation of turbine components, and are also highly necessary and meaningful for the development of advanced high-performance aero-engines. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable pre-swirl nozzle structure and its control method for aero engines, so as to flexibly adjust the flow area of ​​the pre-swirl nozzle, thereby achieving precise control of the pre-swirl nozzle flow rate and pre-swirl performance.

[0006] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0007] An adjustable pre-swivel nozzle structure for an aero-engine includes an inner casing and an outer casing for mounting the aero-engine pre-swivel nozzle. The inner casing and the outer casing are coaxially arranged, and the inner casing, the outer casing, and the pre-swivel nozzle together form a pre-swivel nozzle cooling gas channel. The pre-swivel nozzle includes at least two adjustable pre-swivel nozzle assemblies and multiple fixed pre-swivel nozzle assemblies. The adjustable pre-swivel nozzle assemblies and the fixed pre-swivel nozzle assemblies are circumferentially spaced and evenly distributed between the inner casing and the outer casing. Each adjustable pre-swivel nozzle assembly includes a first pre-swivel nozzle blade, and each fixed pre-swivel nozzle assembly includes a second pre-swivel nozzle blade. The first pre-swivel nozzle blade is movably disposed between the inner casing and the outer casing to adjust the flow area of ​​the pre-swivel nozzle. A limiting component is provided on the inner casing or the outer casing to fix the position of the first pre-swivel nozzle blade.

[0008] Furthermore, the first pre-rotating nozzle blade is provided with a rotating shaft on the end face that mates with the inner wall of the outer casing and the outer wall of the inner casing, and the rotating shafts on both sides of the first pre-rotating nozzle blade are coaxially arranged, with the central axis of the rotating shafts on both sides of the first pre-rotating nozzle blade located on the middle arc line of the first pre-rotating nozzle blade.

[0009] Furthermore, the flow channel structure between the outer casing and the inner casing is provided with a contraction section and a straight blade section in sequence along the airflow direction, and the adjustable pre-swirl nozzle assembly and the fixed pre-swirl nozzle assembly are both disposed within the straight blade section.

[0010] Furthermore, the axial distance between the leading edge of the first pre-swirl nozzle blade and the inlet end of the straight blade section is 0.2 to 1.65 times the chord length of the second pre-swirl nozzle blade, and the axial distance between the trailing edge of the first pre-swirl nozzle blade and the outlet end of the straight blade section is 0.15 to 2.5 times the chord length of the second pre-swirl nozzle blade.

[0011] Furthermore, the height of the second pre-swirling nozzle blade is equal to the height of the flow channel of the straight blade section; the height of the first pre-swirling nozzle blade is 0.85 to 0.95 times the height of the flow channel of the straight blade section, and the first pre-swirling nozzle blade is provided with an adjusting pad that contacts and seals the flow channel wall of the straight blade section corresponding to the outer casing, and the adjusting pad is provided with a through hole through which the rotating shaft can pass.

[0012] To achieve the above-mentioned technical effects, the present invention also provides a control method for an adjustable pre-swirl nozzle structure for an aero-engine, for adjusting the rotation angle of the adjustable pre-swirl nozzle structure for an aero-engine, comprising:

[0013] The target rotation ratio and design total pressure recovery coefficient of the pre-swirl nozzle structure under the design conditions of the aero-engine are obtained. Based on the inlet total pressure, inlet total temperature and design target flow rate of the pre-swirl nozzle under the design conditions of the aero-engine, the equivalent flow rate reference value of the pre-swirl nozzle is analyzed and obtained.

[0014] Under the same pressure ratio as the design conditions of the aero-engine, the aerodynamic parameters of the first pre-swirl nozzle blade of the adjustable pre-swirl nozzle assembly at different rotation angles were obtained. The aerodynamic parameters include the actual total flow rate of the pre-swirl nozzle, the measured inlet total pressure, the measured inlet total temperature, and the measured outlet static pressure, as well as the flow rate at each adjustable pre-swirl nozzle assembly, the flow rate at each fixed pre-swirl nozzle assembly, the actual pre-swirl angle of the outlet airflow of each fixed pre-swirl nozzle assembly, and the rotation speed of the turbine rotor corresponding to the pre-swirl nozzle.

[0015] Based on the aerodynamic parameters of the pre-swirling nozzle and the reference value of the converted flow rate of the pre-swirling nozzle, the actual value of the converted flow rate of the pre-swirling nozzle under the model test conditions is obtained by analysis, and a first functional relationship between the actual value of the converted flow rate of the pre-swirling nozzle under the model test conditions and the reference value of the converted flow rate of the pre-swirling nozzle is constructed.

[0016] Based on the aerodynamic parameters of the pre-swirl nozzle, the airflow rotation ratio at the outlet position of the pre-swirl nozzle under the model test conditions is analyzed and obtained. A second functional relationship is constructed between the airflow rotation ratio at the outlet position of the pre-swirl nozzle under the model test conditions and the target rotation ratio of the pre-swirl nozzle structure design.

[0017] Based on the aerodynamic parameters of the pre-swirl nozzle, the total pressure recovery coefficient of the pre-swirl nozzle under the model test conditions is analyzed and obtained. A third functional relationship is constructed between the total pressure recovery coefficient of the pre-swirl nozzle under the model test conditions and the total pressure recovery coefficient of the pre-swirl nozzle structural design.

[0018] The first pre-rotating nozzle blade rotation angle value of the adjustable pre-rotating nozzle assembly that simultaneously satisfies the first functional relationship, the second functional relationship, and the third functional relationship is taken as the first pre-rotating nozzle blade rotation angle value of the adjustable pre-rotating nozzle assembly under the modeling test conditions.

[0019] Furthermore, the constructed first functional relationship is as follows: Where M is the actual total flow rate of the pre-swirling nozzle under the model test conditions, T1 is the measured total inlet temperature of the pre-swirling nozzle under the model test conditions, and P1 is the measured total inlet pressure of the pre-swirling nozzle under the model test conditions. G QH Here, G represents the converted flow rate reference value for the pre-swirling nozzle under design conditions, and T represents the design target flow rate of the pre-swirling nozzle. tP represents the total inlet temperature of the pre-swirling nozzle under design conditions. t The total inlet pressure of the pre-swirling nozzle under design conditions, ε1 is the upper limit of the absolute value of the relative deviation between the actual value of the converted flow rate of the pre-swirling nozzle and the reference value of the converted flow rate of the pre-swirling nozzle under the model test conditions.

[0020] Furthermore, the constructed second functional relationship is |β-β QH |≤ε2, where β is the airflow rotation ratio analysis value at the pre-swirl nozzle outlet position under the modeling test conditions, β QH ε2 represents the target rotation ratio of the pre-swirling nozzle structure under design conditions, and ε3 represents the upper limit of the absolute value of the deviation between the analyzed value of the airflow rotation ratio at the outlet position of the pre-swirling nozzle and the target rotation ratio of the pre-swirling nozzle structure under the model test conditions. < represents the actual total flow rate of the pre-swirling nozzle under the modeling test conditions, m represents the rotational speed of the turbine rotor corresponding to the pre-swirling nozzle under the modeling test conditions, r represents the radial height of the pre-swirling nozzle, and G represents the total flow rate of the pre-swirling nozzle. i Let be the flow rate value at the i-th adjustable pre-swirl nozzle assembly, s be the number of adjustable pre-swirl nozzle assemblies in the pre-swirl nozzle, and G be the flow rate value at the i-th adjustable pre-swirl nozzle assembly. j Let v be the flow rate at the j-th fixed pre-swirl nozzle assembly, t be the number of fixed pre-swirl nozzle assemblies in the pre-swirl nozzle system, and v be the flow rate at the j-th fixed pre-swirl nozzle assembly. i Let be the circumferential velocity of the airflow at the outlet position of the i-th adjustable pre-swirl nozzle assembly. V j Let be the circumferential velocity of the airflow at the outlet position of the j-th fixed pre-swirl nozzle assembly. θ is the design value of the velocity loss coefficient of the pre-swirl nozzle under the design conditions. i Let a be the rotation angle of the first pre-swirl nozzle blade of the i-th adjustable pre-swirl nozzle assembly. i Let be the actual pre-swirl angle of the outlet airflow of the i-th adjustable pre-swirl nozzle assembly. 'a' represents the target pre-swirl angle of the airflow at the pre-swirl nozzle outlet under design conditions, 'A' represents the design value of the flow area of ​​a single blade throat in the pre-swirl nozzle, and 'x' represents the value of ... i A represents the number of the first pre-swirl nozzle blades in the i-th adjustable pre-swirl nozzle assembly. i Let be the flow area of ​​the i-th adjustable pre-swirling nozzle assembly, k be the gas adiabatic index, R be the gas constant, T1 be the measured inlet total temperature of the pre-swirling nozzle under the modeling test conditions, P1 be the measured inlet total pressure of the pre-swirling nozzle under the modeling test conditions, and P2 be the measured outlet static pressure of the pre-swirling nozzle under the modeling test conditions. Let j be the actual velocity loss coefficient of the j-th fixed pre-swirl nozzle assembly. A j Let x be the actual flow area of ​​the j-th fixed pre-swirl nozzle assembly. jLet a be the number of second pre-swirl nozzle blades in the j-th fixed pre-swirl nozzle assembly. j Let j be the actual pre-swirl angle of the outlet airflow of the j-th fixed pre-swirl nozzle assembly.

[0021] Furthermore, the constructed third functional relation is as follows: Where Cp is the total pressure recovery coefficient of the pre-swirling nozzle under the modeling test conditions. QH ε3 represents the total pressure recovery coefficient of the pre-swirling nozzle structure under design conditions, and ε3 is the upper limit of the absolute value of the relative deviation between the analyzed value of the total pressure recovery coefficient of the pre-swirling nozzle and the total pressure recovery coefficient of the pre-swirling nozzle structure design. M is the actual total flow rate of the pre-swirling nozzle under the model test conditions, H is the flow channel height of the adjustable pre-swirling nozzle blade cascade, r is the radial height of the pre-swirling nozzle, and G... i Let θ be the flow rate value at the i-th adjustable pre-swirl nozzle assembly. i Let be the rotation angle of the first pre-swirl nozzle blade of the i-th adjustable pre-swirl nozzle assembly. G is the design value of the velocity loss coefficient of the pre-swirl nozzle under the design conditions. j Let be the flow rate at the j-th fixed pre-swirl nozzle assembly, s be the number of adjustable pre-swirl nozzle assemblies in the pre-swirl nozzle, and t be the number of fixed pre-swirl nozzle assemblies in the pre-swirl nozzle.

[0022] Compared with the prior art, the beneficial effects of this invention are:

[0023] 1. In this invention, the adjustable pre-swirl nozzle assembly and the fixed pre-swirl nozzle assembly are evenly distributed circumferentially within the pre-swirl nozzle cooling gas channel between the inner and outer casings. The axial position of the first pre-swirl nozzle blade of the adjustable pre-swirl nozzle assembly can be flexibly adjusted to adjust the flow area of ​​the pre-swirl nozzle, thereby achieving precise control of the pre-swirl nozzle flow rate. This effectively solves the problem of adjusting the pre-swirl nozzle during flow rate testing, ensuring that the test flow rate value is qualified and meets the design requirements, fully utilizing the cooling capacity of the pre-swirl nozzle, and achieving the expected cooling effect of the pre-swirl system.

[0024] 2. It can quickly and accurately analyze and obtain the adjustment amount of the first pre-swirl nozzle blade based on the model test conditions. This effectively eliminates the redundant repair or even irreparable damage to the nozzle structure caused by blind operation during the traditional adjustment process, avoiding the waste of production resources. It enables the flow rate to quickly and accurately reach the test target value, improving production efficiency. In addition, the first pre-swirl nozzle blade in each adjustable pre-swirl nozzle assembly is adjusted according to the rotation angle analysis value, ensuring that the adjustment degree is the same within the same adjustable pre-swirl nozzle assembly. This ensures that the cooling air flowing out of the pre-swirl nozzle cooling gas channel has a uniform temperature distribution and consistent cooling effect. While ensuring that the pre-swirl nozzle has sufficient airflow capacity, it also ensures that the pre-swirl nozzle outlet airflow has a suitable rotation ratio and sufficient pressure, thus enabling the pre-swirl nozzle outlet airflow to achieve a relatively ideal pre-swirl performance. This can directly provide important support for the accurate evaluation of the pre-swirl performance of the whole machine pre-swirl air supply system. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the adjustable pre-swirl nozzle structure used in an aero-engine in the embodiment.

[0026] Figure 2 This is a schematic diagram showing the installation position of the first pre-swirl nozzle blade on the inner casing in the embodiment;

[0027] Figure 3 This is a schematic diagram of the structure of the contraction section and the straight blade section in the embodiment;

[0028] Figure 4 This is a schematic diagram of the structure of the first pre-swirl nozzle blade in the embodiment;

[0029] Among them, 1. Inner casing; 2. Outer casing; 3. First pre-rotating nozzle blade; 4. Second pre-rotating nozzle blade; 5. Rotating shaft; 6. Limiting assembly; 7. Middle arc; 8. Retraction section; 9. Straight blade section; 10. Adjusting shim. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0031] Example

[0032] See Figures 1-4An adjustable pre-swivel nozzle structure for an aero-engine includes an inner casing 1 and an outer casing 2 for mounting the aero-engine pre-swivel nozzle. The inner casing 1 and the outer casing 2 are coaxially arranged, and the inner casing 1, the outer casing 2, and the pre-swivel nozzle together constitute a pre-swivel nozzle cooling gas channel. The pre-swivel nozzle includes at least two adjustable pre-swivel nozzle assemblies and multiple fixed pre-swivel nozzle assemblies. The adjustable pre-swivel nozzle assemblies and the fixed pre-swivel nozzle assemblies are circumferentially spaced and evenly distributed between the inner casing 1 and the outer casing 2. Each adjustable pre-swivel nozzle assembly includes a first pre-swivel nozzle blade 3, and each fixed pre-swivel nozzle assembly includes a second pre-swivel nozzle blade 4. The first pre-swivel nozzle blade 3 is movably disposed between the inner casing 1 and the outer casing 2 for adjusting the flow area of ​​the pre-swivel nozzle. A limiting assembly 6 is provided on the inner casing 1 or the outer casing 2 to fix the position of the first pre-swivel nozzle blade 3.

[0033] In this embodiment, at least two adjustable pre-swirl nozzle assemblies are set at the positions where the pre-swirl nozzles are installed in the inner casing 1 and the outer casing 2. The adjustable pre-swirl nozzle assemblies and the fixed pre-swirl nozzle assemblies are evenly distributed circumferentially in the pre-swirl nozzle cooling gas channel between the inner casing 1 and the outer casing 2. The axial position of the first pre-swirl nozzle blade 3 of the adjustable pre-swirl nozzle assembly can be flexibly adjusted according to the flow test results of the adjustable pre-swirl nozzle, so as to adjust the flow area of ​​the pre-swirl nozzle and achieve the purpose of precise control of the pre-swirl nozzle flow rate. This effectively solves the problem of adjusting the pre-swirl nozzle during the flow test inspection, ensures that the test flow rate value is qualified and meets the design requirements, fully utilizes the cooling capacity of the pre-swirl nozzle, and achieves the expected value of the pre-swirl system cooling effect.

[0034] In this embodiment, the first pre-rotating nozzle blade 3 is provided with a rotating shaft 5 on the end face that mates with the inner wall of the outer casing 2 and the outer wall of the inner casing 1, respectively. The rotating shafts 5 on both sides of the first pre-rotating nozzle blade 3 are coaxially arranged, and the central axis of the rotating shafts 5 on both sides of the first pre-rotating nozzle blade 3 is located on the middle arc line 7 of the first pre-rotating nozzle blade 3. Each first pre-rotating nozzle blade 3 adjusts its rotation angle with the rotating shaft 5 as the rotation center. By setting the central axis of the rotating shaft 5 on the middle arc line 7 of the first pre-rotating nozzle blade 3, the consistency of the rotation angle can be maintained, and the amount of change in the rotation angle of the first pre-rotating nozzle blade 3 can be quickly and accurately determined.

[0035] The flow channel structure between the outer casing 2 and the inner casing 1 is provided with a converging section 8 and a straight blade section 9 sequentially along the airflow direction. Both the adjustable pre-swirl nozzle assembly and the fixed pre-swirl nozzle assembly are disposed within the straight blade section 9. The straight blade section 9 ensures that the first pre-swirl nozzle blade 3 remains in contact and sealed with the outer wall of the inner casing 1 and the inner wall of the outer casing 2 during the adjustment of the adjustable pre-swirl nozzle assembly, and that the airflow distribution is not affected by any gaps. Based on the straight blade section 9, the height of the second pre-swirl nozzle blade 4 is equal to the flow channel height of the straight blade section 9; the height of the first pre-swirl nozzle blade 3 is 0.85 to 0.95 times the flow channel height of the straight blade section 9; the first pre-swirl nozzle blade 3 is provided with an adjusting pad 10 that contacts and seals the flow channel wall of the straight blade section 9 corresponding to the outer casing 2. The adjusting pad 10 is generally set as an elastic component, which can always keep the end face of the first pre-swirl nozzle blade 3 facing the inner wall of the outer casing 2 in close contact with the inner wall of the outer casing 2 through the adjusting pad 10, further reducing the problem of gaps during adjustment that affect airflow distribution. In this embodiment, in order to ensure the normal installation of the rotating shaft 5, the adjusting pad 10 is provided with a through hole through which the rotating shaft 5 can pass.

[0036] In this embodiment, the axial distance between the leading edges of the first pre-swirl nozzle blade 3 and the inlet end of the straight blade section 9 and the chord length of the second pre-swirl nozzle blade 4 is 0.2 to 1.65 times the chord length of the second pre-swirl nozzle blade 4, and the axial distance between the trailing edges of the first pre-swirl nozzle blade 3 and the outlet end of the straight blade section 9 and the chord length of the second pre-swirl nozzle blade 4 is 0.15 to 2.5 times the chord length of the second pre-swirl nozzle blade 4. The adjustable pre-swirl nozzle structure in this embodiment adopts a blade-type pre-swirl nozzle structure. The first pre-swirl nozzle blade 3 of the adjustable pre-swirl nozzle assembly and the second pre-swirl nozzle blade 4 of the fixed pre-swirl nozzle assembly both use the same blade shape (chord length of the pre-swirl nozzle blade is S). All the second pre-swirl nozzle blades 4 of the fixed pre-swirl nozzle assembly have the same axial position and are evenly distributed circumferentially to form a uniform pre-swirl nozzle blade channel. The position of the first pre-swirl nozzle blade 3 inside each fixed pre-swirl nozzle assembly can be adjusted as needed.

[0037] Based on the same inventive concept, this embodiment also provides a control method for an adjustable pre-swirl nozzle structure for an aero-engine, including:

[0038] The target rotation ratio and design total pressure recovery coefficient of the pre-swirl nozzle structure under the design conditions of the aero-engine are obtained. Based on the inlet total pressure, inlet total temperature and design target flow rate of the pre-swirl nozzle under the design conditions of the aero-engine, the equivalent flow rate reference value of the pre-swirl nozzle is analyzed and obtained.

[0039] Under the same pressure ratio as the design conditions of the aero-engine, the aerodynamic parameters of the first pre-swirl nozzle blade 3 of the adjustable pre-swirl nozzle assembly were obtained at different rotation angles. The aerodynamic parameters include the actual total flow rate of the pre-swirl nozzle, the measured inlet total pressure, the measured inlet total temperature, and the measured outlet static pressure, as well as the flow rate at each adjustable pre-swirl nozzle assembly, the flow rate at each fixed pre-swirl nozzle assembly, the actual pre-swirl angle of the outlet airflow of each fixed pre-swirl nozzle assembly, and the rotation speed of the turbine rotor corresponding to the pre-swirl nozzle.

[0040] Based on the aerodynamic parameters of the pre-swirling nozzle and the reference value of the converted flow rate of the pre-swirling nozzle, the actual value of the converted flow rate of the pre-swirling nozzle under the model test conditions is obtained by analysis, and a first functional relationship between the actual value of the converted flow rate of the pre-swirling nozzle under the model test conditions and the reference value of the converted flow rate of the pre-swirling nozzle is constructed.

[0041] Based on the aerodynamic parameters of the pre-swirl nozzle, the airflow rotation ratio at the outlet position of the pre-swirl nozzle under the model test conditions is analyzed and obtained. A second functional relationship is constructed between the airflow rotation ratio at the outlet position of the pre-swirl nozzle under the model test conditions and the target rotation ratio of the pre-swirl nozzle structure design.

[0042] Based on the aerodynamic parameters of the pre-swirl nozzle, the total pressure recovery coefficient of the pre-swirl nozzle under the model test conditions is analyzed and obtained. A third functional relationship is constructed between the total pressure recovery coefficient of the pre-swirl nozzle under the model test conditions and the total pressure recovery coefficient of the pre-swirl nozzle structural design.

[0043] The rotation angle value of the first pre-rotating nozzle blade 3 of the adjustable pre-rotating nozzle assembly that simultaneously satisfies the first functional relationship, the second functional relationship, and the third functional relationship is taken as the rotation angle value of the first pre-rotating nozzle blade 3 of the adjustable pre-rotating nozzle assembly under the modeling test conditions.

[0044] In this embodiment, the adjustment amount of the first pre-swirl nozzle blade 3 can be quickly and accurately analyzed and obtained according to the model test conditions. This can effectively eliminate the redundant repair or even irreparable damage to the nozzle structure caused by blind operation in the traditional adjustment process, avoid the waste of production resources, and enable the flow rate to reach the test target value quickly and accurately, thereby improving production efficiency. In addition, the first pre-swirl nozzle blade 3 in each adjustable pre-swirl nozzle assembly is adjusted according to the rotation angle analysis value to ensure that the adjustment degree in the same adjustable pre-swirl nozzle assembly is the same. This can ensure that the cooling air flowing out of the cooling gas channel of the pre-swirl nozzle has a uniform temperature distribution and consistent cooling effect, avoiding the harm of thermal stress caused by concentrated cooling of turbine components.

[0045] In this embodiment, the constructed first functional relation is: Where M is the actual total flow rate of the pre-swirling nozzle under the model test conditions, T1 is the measured total inlet temperature of the pre-swirling nozzle under the model test conditions, and P1 is the measured total inlet pressure of the pre-swirling nozzle under the model test conditions. G QH Here, G represents the converted flow rate reference value for the pre-swirling nozzle under design conditions, and T represents the design target flow rate of the pre-swirling nozzle. t P represents the total inlet temperature of the pre-swirling nozzle under design conditions. t The total inlet pressure of the pre-swirling nozzle under design conditions, ε1 is the upper limit of the absolute value of the relative deviation between the actual value of the converted flow rate of the pre-swirling nozzle and the reference value of the converted flow rate of the pre-swirling nozzle under the model test conditions.

[0046] The constructed second functional relationship is |β-β QH |≤ε2, where β is the airflow rotation ratio analysis value at the pre-swirl nozzle outlet position under the modeling test conditions, β QH ε2 represents the target rotation ratio of the pre-swirling nozzle structure under design conditions, and ε3 represents the upper limit of the absolute value of the deviation between the analyzed value of the airflow rotation ratio at the outlet position of the pre-swirling nozzle and the target rotation ratio of the pre-swirling nozzle structure under the model test conditions. M is the actual total flow rate of the pre-swirl nozzle under the model test conditions, n is the rotational speed of the turbine rotor corresponding to the pre-swirl nozzle under the model test conditions, r is the radial height of the pre-swirl nozzle, and G... i Let be the flow rate value at the i-th adjustable pre-swirl nozzle assembly, s be the number of adjustable pre-swirl nozzle assemblies in the pre-swirl nozzle, and G be the flow rate value at the i-th adjustable pre-swirl nozzle assembly. j Let V be the flow rate at the j-th fixed pre-swirl nozzle assembly, t be the number of fixed pre-swirl nozzle assemblies in the pre-swirl nozzle system, and V be the flow rate at the j-th fixed pre-swirl nozzle assembly. i Let be the circumferential velocity of the airflow at the outlet position of the i-th adjustable pre-swirl nozzle assembly. V j Let be the circumferential velocity of the airflow at the outlet position of the j-th fixed pre-swirl nozzle assembly. θ is the design value of the velocity loss coefficient of the pre-swirl nozzle under the design conditions. i Let a be the rotation angle of the first pre-swirl nozzle blade 3 of the i-th adjustable pre-swirl nozzle assembly. i Let be the actual pre-swirl angle of the outlet airflow of the i-th adjustable pre-swirl nozzle assembly. 'a' represents the target pre-swirl angle of the airflow at the pre-swirl nozzle outlet under design conditions, 'A' represents the design value of the flow area of ​​a single blade throat in the pre-swirl nozzle, and 'x' represents the value of ... i A represents the number of first pre-swirl nozzle blades 3 in the i-th adjustable pre-swirl nozzle assembly. iLet be the flow area of ​​the i-th adjustable pre-swirling nozzle assembly, k be the gas adiabatic index, R be the gas constant, T1 be the measured inlet total temperature of the pre-swirling nozzle under the modeling test conditions, P1 be the measured inlet total pressure of the pre-swirling nozzle under the modeling test conditions, and P2 be the measured outlet static pressure of the pre-swirling nozzle under the modeling test conditions. Let j be the actual velocity loss coefficient of the j-th fixed pre-swirl nozzle assembly. A j Let x be the actual flow area of ​​the j-th fixed pre-swirl nozzle assembly. j The number of second pre-swirl nozzle blades 4 in the j-th fixed pre-swirl nozzle assembly, a j Let j be the actual pre-swirl angle of the outlet airflow of the j-th fixed pre-swirl nozzle assembly.

[0047] The constructed third functional relation is as follows: Where Cp is the total pressure recovery coefficient of the pre-swirling nozzle under the modeling test conditions. QH ε3 represents the total pressure recovery coefficient of the pre-swirling nozzle structure under design conditions, and ε3 is the upper limit of the absolute value of the relative deviation between the analyzed value of the total pressure recovery coefficient of the pre-swirling nozzle and the total pressure recovery coefficient of the pre-swirling nozzle structure design. M is the actual total flow rate of the pre-swirling nozzle under the model test conditions, H is the flow channel height of the adjustable pre-swirling nozzle blade cascade, r is the radial height of the pre-swirling nozzle, and G... i Let θ be the flow rate value at the i-th adjustable pre-swirl nozzle assembly. i Let be the rotation angle of the first pre-rotating nozzle blade 3 of the i-th adjustable pre-rotating nozzle assembly. G is the design value of the velocity loss coefficient of the pre-swirl nozzle under the design conditions. j Let be the flow rate at the j-th fixed pre-swirl nozzle assembly, s be the number of adjustable pre-swirl nozzle assemblies in the pre-swirl nozzle, and t be the number of fixed pre-swirl nozzle assemblies in the pre-swirl nozzle.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adjustable pre-swirl nozzle structure for an aero-engine, comprising an inner casing and an outer casing for mounting the aero-engine pre-swirl nozzle, wherein the inner casing and the outer casing are coaxially arranged, and the inner casing, the outer casing, and the pre-swirl nozzle together constitute a pre-swirl nozzle cooling gas passage; characterized in that, The pre-rotating nozzle includes at least two adjustable pre-rotating nozzle assemblies and multiple fixed pre-rotating nozzle assemblies. The adjustable and fixed pre-rotating nozzle assemblies are circumferentially spaced and evenly distributed between the inner and outer casings. Each adjustable pre-rotating nozzle assembly includes a first pre-rotating nozzle blade, and each fixed pre-rotating nozzle assembly includes a second pre-rotating nozzle blade. The first pre-rotating nozzle blade is movably disposed between the inner and outer casings to adjust the flow area of ​​the pre-rotating nozzle. The inner or outer casing is provided with a limiting component that can fix the position of the first pre-rotating nozzle blade.

2. The adjustable pre-swirl nozzle structure for an aero-engine according to claim 1, characterized in that, The first pre-rotating nozzle blade is provided with a rotating shaft on the end face that mates with the inner wall of the outer casing and the outer wall of the inner casing, and the rotating shafts on both sides of the first pre-rotating nozzle blade are coaxially arranged, and the central axis of the rotating shafts on both sides of the first pre-rotating nozzle blade is located on the middle arc line of the first pre-rotating nozzle blade.

3. The adjustable pre-swirl nozzle structure for an aero-engine according to claim 1, characterized in that, The flow channel structure between the outer casing and the inner casing is provided with a contraction section and a straight blade section in sequence along the airflow direction. The adjustable pre-swirl nozzle assembly and the fixed pre-swirl nozzle assembly are both disposed within the straight blade section.

4. The adjustable pre-swirl nozzle structure for an aero-engine according to claim 3, characterized in that, The axial distance between the leading edge of the first pre-swirl nozzle blade and the inlet end of the straight blade section is 0.2 to 1.65 times the chord length of the second pre-swirl nozzle blade, and the axial distance between the trailing edge of the first pre-swirl nozzle blade and the outlet end of the straight blade section is 0.15 to 2.5 times the chord length of the second pre-swirl nozzle blade.

5. The adjustable pre-swirl nozzle structure for an aero-engine according to claim 3, characterized in that, The height of the second pre-swirling nozzle blade is equal to the height of the flow channel of the straight blade section; the height of the first pre-swirling nozzle blade is 0.85 to 0.95 times the height of the flow channel of the straight blade section; the first pre-swirling nozzle blade is provided with an adjusting pad that contacts and seals the flow channel wall of the straight blade section corresponding to the outer casing; the adjusting pad is provided with a through hole through which the rotating shaft can pass.

6. A control method for an adjustable pre-swirl nozzle structure for an aero-engine, used to adjust the rotation angle of the adjustable pre-swirl nozzle structure for an aero-engine as described in claim 1, characterized in that, include: The target rotation ratio and design total pressure recovery coefficient of the pre-swirl nozzle structure under the design conditions of the aero-engine are obtained. Based on the inlet total pressure, inlet total temperature and design target flow rate of the pre-swirl nozzle under the design conditions of the aero-engine, the equivalent flow rate reference value of the pre-swirl nozzle is analyzed and obtained. Under the same pressure ratio as the design conditions of the aero-engine, the aerodynamic parameters of the first pre-swirl nozzle blade of the adjustable pre-swirl nozzle assembly at different rotation angles were obtained. The aerodynamic parameters include the actual total flow rate of the pre-swirl nozzle, the measured inlet total pressure, the measured inlet total temperature, and the measured outlet static pressure, as well as the flow rate at each adjustable pre-swirl nozzle assembly, the flow rate at each fixed pre-swirl nozzle assembly, the actual pre-swirl angle of the outlet airflow of each fixed pre-swirl nozzle assembly, and the rotation speed of the turbine rotor corresponding to the pre-swirl nozzle. Based on the aerodynamic parameters of the pre-swirling nozzle and the reference value of the converted flow rate of the pre-swirling nozzle, the actual value of the converted flow rate of the pre-swirling nozzle under the model test conditions is obtained by analysis, and a first functional relationship between the actual value of the converted flow rate of the pre-swirling nozzle under the model test conditions and the reference value of the converted flow rate of the pre-swirling nozzle is constructed. Based on the aerodynamic parameters of the pre-swirl nozzle, the airflow rotation ratio at the outlet position of the pre-swirl nozzle under the model test conditions is analyzed and obtained. A second functional relationship is constructed between the airflow rotation ratio at the outlet position of the pre-swirl nozzle under the model test conditions and the target rotation ratio of the pre-swirl nozzle structure design. Based on the aerodynamic parameters of the pre-swirl nozzle, the total pressure recovery coefficient of the pre-swirl nozzle under the model test conditions is analyzed and obtained. A third functional relationship is constructed between the total pressure recovery coefficient of the pre-swirl nozzle under the model test conditions and the total pressure recovery coefficient of the pre-swirl nozzle structural design. The first pre-rotating nozzle blade rotation angle value of the adjustable pre-rotating nozzle assembly that simultaneously satisfies the first functional relationship, the second functional relationship, and the third functional relationship is taken as the first pre-rotating nozzle blade rotation angle value of the adjustable pre-rotating nozzle assembly under the modeling test conditions.

7. The control method for an adjustable pre-swirl nozzle structure for an aero-engine according to claim 6, characterized in that, The first functional relation constructed is as follows Where M is the actual total flow rate of the pre-swirling nozzle under the model test conditions, T1 is the measured total inlet temperature of the pre-swirling nozzle under the model test conditions, and P1 is the measured total inlet pressure of the pre-swirling nozzle under the model test conditions. G QH Here, G represents the converted flow rate reference value for the pre-swirling nozzle under design conditions, and T represents the design target flow rate of the pre-swirling nozzle. t P represents the total inlet temperature of the pre-swirling nozzle under design conditions. t The total inlet pressure of the pre-swirling nozzle under design conditions, ε1 is the upper limit of the absolute value of the relative deviation between the actual value of the converted flow rate of the pre-swirling nozzle and the reference value of the converted flow rate of the pre-swirling nozzle under the model test conditions.

8. The control method for an adjustable pre-swirl nozzle structure for an aero-engine according to claim 6, characterized in that, The constructed second functional relationship is |β-β QH |≤ε2, where β is the airflow rotation ratio analysis value at the pre-swirl nozzle outlet position under the modeling test conditions, β QH ε2 represents the target rotation ratio of the pre-swirling nozzle structure under design conditions, and ε3 represents the upper limit of the absolute value of the deviation between the analyzed value of the airflow rotation ratio at the outlet position of the pre-swirling nozzle and the target rotation ratio of the pre-swirling nozzle structure under the model test conditions. M is the actual total flow rate of the pre-swirl nozzle under the model test conditions, n is the rotational speed of the turbine rotor corresponding to the pre-swirl nozzle under the model test conditions, r is the radial height of the pre-swirl nozzle, and G... i Let be the flow rate value at the i-th adjustable pre-swirl nozzle assembly, s be the number of adjustable pre-swirl nozzle assemblies in the pre-swirl nozzle, and G be the flow rate value at the i-th adjustable pre-swirl nozzle assembly. j Let V be the flow rate at the j-th fixed pre-swirl nozzle assembly, t be the number of fixed pre-swirl nozzle assemblies in the pre-swirl nozzle system, and V be the flow rate at the j-th fixed pre-swirl nozzle assembly. i Let be the circumferential velocity of the airflow at the outlet position of the i-th adjustable pre-swirl nozzle assembly. V j Let be the circumferential velocity of the airflow at the outlet position of the j-th fixed pre-swirl nozzle assembly. θ is the design value of the velocity loss coefficient of the pre-swirl nozzle under the design conditions. i Let a be the rotation angle of the first pre-swirl nozzle blade of the i-th adjustable pre-swirl nozzle assembly. i Let be the actual pre-swirl angle of the outlet airflow of the i-th adjustable pre-swirl nozzle assembly. 'a' represents the target pre-swirl angle of the airflow at the pre-swirl nozzle outlet under design conditions, 'A' represents the design value of the flow area of ​​a single blade throat in the pre-swirl nozzle, and 'x' represents the value of ... i A represents the number of the first pre-swirl nozzle blades in the i-th adjustable pre-swirl nozzle assembly. i Let be the flow area of ​​the i-th adjustable pre-swirling nozzle assembly, k be the gas adiabatic index, R be the gas constant, T1 be the measured inlet total temperature of the pre-swirling nozzle under the modeling test conditions, P1 be the measured inlet total pressure of the pre-swirling nozzle under the modeling test conditions, and P2 be the measured outlet static pressure of the pre-swirling nozzle under the modeling test conditions. Let j be the actual velocity loss coefficient of the j-th fixed pre-swirl nozzle assembly. A j Let x be the actual flow area of ​​the j-th fixed pre-swirl nozzle assembly. j Let a be the number of second pre-swirl nozzle blades in the j-th fixed pre-swirl nozzle assembly. j Let j be the actual pre-swirl angle of the outlet airflow of the j-th fixed pre-swirl nozzle assembly.

9. The control method for an adjustable pre-swirl nozzle structure for an aero-engine according to claim 6, characterized in that, The constructed third functional relation is as follows: Where Cp is the total pressure recovery coefficient of the pre-swirling nozzle under the modeling test conditions. QH ε3 represents the total pressure recovery coefficient of the pre-swirling nozzle structure under design conditions, and ε3 is the upper limit of the absolute value of the relative deviation between the analyzed value of the total pressure recovery coefficient of the pre-swirling nozzle and the total pressure recovery coefficient of the pre-swirling nozzle structure design. M is the actual total flow rate of the pre-swirling nozzle under the model test conditions, H is the flow channel height of the adjustable pre-swirling nozzle blade cascade, r is the radial height of the pre-swirling nozzle, and G... i Let θ be the flow rate value at the i-th adjustable pre-swirl nozzle assembly. i Let be the rotation angle of the first pre-swirl nozzle blade of the i-th adjustable pre-swirl nozzle assembly. G is the design value of the velocity loss coefficient of the pre-swirl nozzle under the design conditions. j Let be the flow rate at the j-th fixed pre-swirl nozzle assembly, s be the number of adjustable pre-swirl nozzle assemblies in the pre-swirl nozzle, and t be the number of fixed pre-swirl nozzle assemblies in the pre-swirl nozzle.

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