A method for determining the characteristics of an aeroengine anti-icing system based on whole-engine testing

Abstract

This application belongs to the technical field of engine design, and particularly relates to a method for determining the characteristics of an anti-icing system for an aero-engine based on a whole-engine test. The method includes: Step S1, modeling the flow path of the anti-icing system with a number of heat exchange units and a number of flow resistance units to obtain an initial anti-icing system characteristic model, and calculating the first anti-icing system parameters at multiple incoming flow Reynolds numbers; Step S2, conducting a whole-engine test of the aero-engine under non-icing conditions, and calculating the second anti-icing system parameters at multiple incoming flow Reynolds numbers; Step S3, adjusting the initial anti-icing system characteristic model so that the first anti-icing system parameters obtained based on the initial anti-icing system characteristic model and the second anti-icing system parameters are within a preset deviation range, and obtaining an adjusted anti-icing system characteristic model. This application can obtain the flow and heat transfer characteristics of the anti-icing system based on a whole-engine test that meet the engineering requirements.

Description

Technical Field

[0001] This application belongs to the technical field of engine design, and particularly relates to a method for determining the characteristics of an anti-icing system for an aero-engine based on a whole-engine test. Background Art

[0002] When an aircraft flies within the icing envelope, due to the presence of supercooled water droplets in the air, the surfaces of the engine inlet components will freeze. The icing of the engine inlet components will change their aerodynamic shapes, resulting in a decline in aerodynamic performance. At the same time, it will reduce the intake area of the airflow, and the shedding of ice accumulation will also damage the engine components, causing mechanical damage. Therefore, anti-icing protection is required for the engine inlet components. The flow and heat transfer characteristics of the anti-icing system are the prerequisite for evaluating the anti-icing effect. Only by obtaining the accurate flow and heat transfer conditions of the anti-icing system can the true anti-icing effect of the anti-icing system be evaluated, and then it can be judged whether the anti-icing system design is reasonable and whether it needs to be improved.

[0003] Since there is no test bench that can carry out whole-engine environmental icing tests, and the component-level and part-level tests cannot take into account the circumferential flow and heat transfer characteristics of the anti-icing air supply system, the influence of the upstream and downstream systems, and various whole-engine factors (such as whole-engine vibration) under the actual operating conditions of the engine. Therefore, it is impossible to obtain the flow and heat transfer characteristics of the anti-icing system through whole-engine tests under icing conditions.

[0004] The existing methods for obtaining the flow and heat transfer characteristics of the anti-icing system include component tests and three-dimensional numerical simulations. However, component tests have the disadvantages of large deviation and long calculation cycle. Specifically, the flow field and temperature field distributions of the anti-icing components are obtained by carrying out three-dimensional anti-icing system flow and heat transfer simulations using commercial software. This method has a long cycle, complex procedures, poor model adaptability and convergence, and the calculation results may deviate greatly from the actual situation; the three-dimensional model is not adjustable or the adjustment is relatively complex. After adjustment, it is necessary to reconstruct the mesh for calculation, which is rather cumbersome; in the preliminary work of multi-scheme design comparison, multi-state analysis, and troubleshooting analysis, etc., it is impossible to quickly and effectively obtain the evaluation results of the anti-icing ability. Summary of the Invention

[0005] In order to solve one of the above problems, this application provides a method for determining the characteristics of an anti-icing system for an aero-engine based on a whole-engine test, providing technical support for subsequent obtaining the anti-icing effect evaluation of the anti-icing system.

[0006] The method for determining the characteristics of an anti-icing system for an aero-engine based on a whole-engine test provided by this application mainly includes:

[0007] Step S1: Model the flow path of the anti-icing system with a number of heat exchange units and a number of flow resistance units to obtain an initial anti-icing system characteristic model, and based on the initial anti-icing system characteristic model, obtain the first air intake volume of the anti-icing system, the first temperature drop and the first flow resistance of each structure at multiple incoming flow Reynolds numbers;

[0008] Step S2: Conduct an overall aero-engine test under non-icing conditions, and calculate the second anti-icing system air extraction volume, the second temperature drop and the second flow resistance of each structure at the multiple incoming flow Reynolds numbers based on the temperature and pressure parameters collected by multiple temperature and pressure sensors arranged on the flow path of the anti-icing system.

[0009] Step S3: Adjust the initial anti-icing system characteristic model so that the first anti-icing system air extraction volume obtained based on the initial anti-icing system characteristic model and the second anti-icing system air extraction volume are within a preset deviation range, the first temperature drop of each structure obtained based on the initial anti-icing system characteristic model and the second temperature drop of each structure are within a preset deviation range, and the first flow resistance of each structure obtained based on the initial anti-icing system characteristic model and the second flow resistance of each structure are within a preset deviation range, thereby obtaining an adjusted anti-icing system characteristic model.

[0010] Preferably, after step S3, it further includes:

[0011] Step S4: Based on the adjusted anti-icing system characteristic model, calculate the anti-icing air extraction volume, the temperature drop and the flow resistance of each structure under multiple working conditions under icing conditions.

[0012] Step S5: Conduct component-level tests for the multiple working conditions under icing conditions to verify the adjusted anti-icing system characteristic model.

[0013] Preferably, in step S1, the first temperature drop and the first flow resistance of each structure include: the first temperature drop and the first flow resistance of the plenum chamber, the first temperature drop and the first flow resistance of each fairing strut; in step S2, the second temperature drop and the second flow resistance of each structure include: the second temperature drop and the second flow resistance of the plenum chamber, the second temperature drop and the second flow resistance of each fairing strut.

[0014] Preferably, in step S2, the multiple temperature and pressure sensors arranged on the flow path of the anti-icing system include:

[0015] Arrange total temperature Tt1 and static pressure Ps1 measurement points at a certain cross-section of the upstream air intake pipe of the control accessory;

[0016] Arrange total temperature Tt2, total pressure Pt2 and static pressure Ps2 measurement points at a certain cross-section of the downstream air intake pipe of the control accessory;

[0017] Arrange temperature Tj1 and pressure Pj1 measurement points at the hot air inlet of the plenum chamber, and arrange temperature Tj2 and pressure Pj2 measurement points at the farthest point of the hot air travel distance from the hot air inlet of the plenum chamber;

[0018] Arrange pressure Tz1 - Tz4 and temperature Pz1 - Pz4 measurement points at the inlet of the fairing strut, and arrange pressure Tc1 - Tc4 and temperature Pc1 - Pc4 measurement points at the outlet of the fairing strut;

[0019] Among them, the high-pressure compressor is connected to the air extraction seat of the anti-icing system through an air extraction pipe, the air extraction seat of the anti-icing system is connected to the hot air inlet of the air collection cavity, the air collection cavity is an annular cavity, and is connected to a hood located at the center of the annular cavity through a plurality of rectifying splints, and a control accessory is arranged on the air extraction pipe.

[0020] Preferably, in step S2, determining the air extraction volume of the second anti-icing system includes:

[0021] Obtaining the ideal flow rate of the anti-icing system;

[0022] Determining the flow coefficient based on the total static pressure ratio of the air extraction pipe in front of the air extraction seat of the anti-icing system, wherein the relationship between the total static pressure ratio and the flow coefficient is obtained through a flow rate verification test;

[0023] Determining the air extraction volume of the second anti-icing system based on the ideal flow rate and the flow coefficient.

[0024] Preferably, in step S2, determining the second temperature drop and the second flow resistance of each structure includes:

[0025] Determining the second temperature drop of the air collection cavity based on the temperature Tj1 measurement point arranged at the hot air inlet of the air collection cavity and the temperature Tj2 measurement point arranged at the farthest point of the hot air travel distance from the hot air inlet of the air collection cavity;

[0026] Determining the second flow resistance of the air collection cavity based on the pressure Pj1 measurement point arranged at the hot air inlet of the air collection cavity and the pressure Pj2 measurement point arranged at the farthest point of the hot air travel distance from the hot air inlet of the air collection cavity;

[0027] Determining the second temperature drop of the rectifying splint based on the temperature Pz1-Pz4 measurement points arranged at the inlet of the rectifying splint and the temperature Pc1-Pc4 measurement points arranged at the outlet of the rectifying splint;

[0028] Determining the second flow resistance of the rectifying splint based on the pressure Tz1-Tz4 measurement points arranged at the inlet of the rectifying splint and the pressure Tc1-Tc4 measurement points arranged at the outlet of the rectifying splint.

[0029] Preferably, in step S3, the preset deviation range is 10%.

[0030] Preferably, in step S3, adjusting the initial anti-icing system characteristic model includes:

[0031] Adjusting the flow capacity of the flow resistance unit by adjusting the cross-sectional parameters of the throttle holes and exhaust holes of the air extraction pipe and the rectifying splint, or by adjusting the turning size parameters of the air extraction pipe;

[0032] Adjusting the heat exchange capacity of the heat exchange unit by adjusting the heat exchange area and heat conduction area parameters of each structure.

[0033] This application corrects the existing calculation model through the whole-machine test data, making the modeling of the anti-icing flow path more realistic and reliable, and obtaining the flow and heat transfer characteristics of the anti-icing system based on the whole-machine test that meet the engineering requirements. Description of the Drawings

[0034] Figure 1 It is a flowchart of a preferred embodiment of the method for determining the characteristics of an aero-engine anti-icing system based on the whole-machine test of this application.

[0035] Figure 2 For this application Figure 1 Front view of the anti-icing system of the illustrated embodiment.

[0036] Figure 3 For this application Figure 1 Schematic diagram of the measuring point arrangement at the air supply pipe of the anti-icing system of the illustrated embodiment.

[0037] Figure 4 For this application Figure 1 Schematic diagram of the measuring point arrangement of the cavity temperature and cavity pressure of the anti-icing system of the illustrated embodiment.

[0038] Figure 5 Schematic diagram of the modeled flow path of the anti-icing system.

[0039] Wherein, 1 - air supply seat of the anti-icing system, 2 - air collecting cavity, 3 - rectifying support plate, 4 - cap, 5 - high-pressure compressor, 6 - air supply pipe, 7 - control accessory. Detailed Embodiment

[0040] To make the purpose, technical solution and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the drawings in the embodiments of this application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some but not all of the embodiments of this application. The embodiments described below with reference to the drawings are exemplary and are intended to explain this application and should not be construed as limiting this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the drawings.

[0041] This application provides a method for determining the characteristics of an aero-engine anti-icing system based on the whole-machine test, as Figure 1 shown, mainly including:

[0042] Step S1: Model the flow path of the anti-icing system with a number of heat exchange units and a number of flow resistance units to obtain an initial anti-icing system characteristic model, and based on the initial anti-icing system characteristic model, obtain the first anti-icing system air extraction volume, the first temperature drop and the first flow resistance of each structure at multiple incoming flow Reynolds numbers;

[0043] Step S2: Conduct an overall aero-engine test under non-icing conditions, and calculate the second anti-icing system air extraction volume, the second temperature drop and the second flow resistance of each structure at the multiple incoming flow Reynolds numbers based on the temperature and pressure parameters collected by a number of temperature and pressure sensors arranged on the anti-icing system flow path;

[0044] Step S3: Adjust the initial anti-icing system characteristic model so that the first anti-icing system air extraction volume obtained based on the initial anti-icing system characteristic model and the second anti-icing system air extraction volume are within a preset deviation range, the first temperature drop of each structure obtained based on the initial anti-icing system characteristic model and the second temperature drop of each structure are within a preset deviation range, and the first flow resistance of each structure obtained based on the initial anti-icing system characteristic model and the second flow resistance of each structure are within a preset deviation range, thereby obtaining an adjusted anti-icing system characteristic model.

[0045] In this application, a series of flow and heat exchange units are used to model the anti-icing hot air flow path, and a one-dimensional algorithm is used to obtain the flow and heat transfer characteristics of each unit, that is, the initial anti-icing system characteristic model. Subsequently, the above calculation model is corrected by the engine overall cavity temperature, cavity pressure, and wall temperature test data to obtain the one-dimensional flow and heat transfer characteristics of the anti-icing system under the actual operating conditions of the engine, that is, the adjusted anti-icing system characteristic model.

[0046] In some alternative embodiments, after step S3, it further includes:

[0047] Step S4: Based on the adjusted anti-icing system characteristic model, calculate the anti-icing air extraction volume, the temperature drop and the flow resistance of each structure under multiple working conditions under icing conditions;

[0048] Step S5: Conduct component-level tests for the multiple working conditions under icing conditions to verify the adjusted anti-icing system characteristic model.

[0049] This embodiment is verified through component-level anti-icing effect tests to obtain a calculation method with accuracy and accuracy meeting the engineering requirements. If the adjusted anti-icing system characteristic model in step S5 cannot pass the verification, return to step S3 and readjust the initial anti-icing system characteristic model.

[0050] In some alternative embodiments, in step S1, the first temperature drop and the first flow resistance of each structure include: the first temperature drop and the first flow resistance of the air collecting cavity, and the first temperature drop and the first flow resistance of each flow rectifying plate; in step S2, the second temperature drop and the second flow resistance of each structure include: the second temperature drop and the second flow resistance of the air collecting cavity, and the second temperature drop and the second flow resistance of each flow rectifying plate.

[0051] As Figure 2 and Figure 3 shown, a schematic diagram of a typical engine anti-icing system is given, and the components included are the anti-icing system air extraction seat 1, the air collecting cavity 2, the flow rectifying plates 3, and the cowl 4. The components that need anti-icing protection are the flow rectifying plates 3 and the cowl 4. The high-pressure hot air from the high-pressure compressor enters the anti-icing system air extraction seat 1 through the supply pipeline via the control accessory, then enters the air collecting cavity 2, and then flows to the flow rectifying plates 3. The hot air entering the flow rectifying plates 3 heats their walls, and then a part of the hot air flows into the mainstream through the exhaust holes, and another part flows into the cowl 4 through the ventilation holes of the mounting seat behind the cowl 4 to provide anti-icing protection for the cowl 4. In alternative embodiments, the anti-icing system can be any form of flow path layout, and the temperature drops and flow resistances of the corresponding structures are also different.

[0052] In step S1 of this application, the modeling of the anti-icing system mainly refers to modeling the anti-icing system air duct 6, the air collecting cavity 2, the flow rectifying plates 3, and the cowl 4 in the direction of the anti-icing hot air flow. It should be noted that the anti-icing system involves multiple flow rectifying plates 3. In order to obtain the characteristics of the entire anti-icing system loop for facilitating correction using the test data of the whole machine, it is necessary to model each flow rectifying plate 3 separately. At the same time, when modeling, the circumferential flow and heat transfer characteristics of the air collecting cavity 2 should be considered emphatically. Each anti-icing component is modeled into corresponding flow or heat transfer units according to its flow and heat transfer characteristics, and the flow resistance and heat transfer characteristics of different units are calculated through empirical formulas obtained by conducting component tests or other means, so as to obtain the flow and heat transfer characteristics of the entire system.

[0053] As Figure 5 shown, in a specific embodiment, the anti-icing system with a typical structure is modeled to form a calculation network. The final modeling result is 246 heat transfer units and 153 flow resistance units. Through one-dimensional calculation, when the incoming flow Reynolds number Re is 2.6×10 7 , 6.5×10 7 , 1.17×10 8 , the air extraction amounts of the anti-icing system are 140, 150, and 152 g / s respectively, the temperature drop of the air collecting cavity is 54, 78, and 150 K, the flow resistance of the air collecting cavity is 5, 20, and 19 kPa, the temperature drop of the plate is 20, 40, and 50 K, and the flow resistance of the plate is 6.5, 10.4, and 10.5 kPa. The above parameters correspond to the first air extraction amount of the anti-icing system, the first temperature drop and the first flow resistance of each structure in step S1.

[0054] Before step S2, it is necessary to measure the pressure and temperature parameters at the specified positions by arranging sensors at the measuring points in the entire anti-icing system for use in the calculation of step S2. In some alternative embodiments, in step S2, multiple temperature and pressure sensors arranged on the flow path of the anti-icing system, such as Figure 3 and Figure 4 shown, mainly include:

[0055] Arrange total temperature Tt1 and static pressure Ps1 measuring points at a certain cross-section of the upstream air duct of the control accessory 7;

[0056] Arrange total temperature Tt2, total pressure Pt2, and static pressure Ps2 measuring points at a certain cross-section of the downstream air duct of the control accessory 7;

[0057] Arrange temperature Tj1 and pressure Pj1 measuring points at the hot air inlet of the air collection chamber 2, and arrange temperature Tj2 and pressure Pj2 measuring points at the farthest point of the hot air travel distance from the hot air inlet of the air collection chamber 2;

[0058] Arrange pressure Tz1 - Tz4 and temperature Pz1 - Pz4 measuring points at the inlet of the fairing strut 3, and arrange pressure Tc1 - Tc4 and temperature Pc1 - Pc4 measuring points at the outlet of the fairing strut 3;

[0059] Among them, the high-pressure compressor 5 is connected to the anti-icing system air extraction seat 1 through the air duct 6, the anti-icing system air extraction seat 1 is connected to the hot air inlet of the air collection chamber 2, the air collection chamber 2 is an annular chamber, and is connected to the cap 4 located at the center of the annular chamber through multiple fairing struts 3, and the control accessory 7 is arranged on the air duct 6.

[0060] In some alternative embodiments, in step S2, determining the second anti-icing system air extraction volume includes:

[0061] Obtain the ideal flow rate of the anti-icing system;

[0062] Determine the flow coefficient based on the total static pressure ratio of the air duct 6 in front of the anti-icing system air extraction seat 1 of the anti-icing system, where the relationship between the total static pressure ratio and the flow coefficient is obtained through a flow calibration test;

[0063] Determine the second anti-icing system air extraction volume based on the ideal flow rate and the flow coefficient.

[0064] Specifically, calculate the anti-icing system air extraction volume according to formulas (1) - (4)

[0065]

[0066]

[0067]

[0068]

[0069] Where Ma is the Mach number; k is a coefficient, and for air, k = 1.4; μ is the flow coefficient, which is obtained through the flow characteristic test of the air intake pipe.

[0070] In some alternative embodiments, in step S2, determining the second temperature drop and the second flow resistance of each structure includes:

[0071] Determining the second temperature drop of the gas collecting chamber based on the temperature Tj1 measurement point arranged at the hot gas inlet of the gas collecting chamber 2 and the temperature Tj2 measurement point arranged at the farthest point of the hot gas travel distance from the hot gas inlet of the gas collecting chamber 2;

[0072] Determining the second flow resistance of the gas collecting chamber based on the pressure Pj1 measurement point arranged at the hot gas inlet of the gas collecting chamber 2 and the pressure Pj2 measurement point arranged at the farthest point of the hot gas travel distance from the hot gas inlet of the gas collecting chamber 2;

[0073] Determining the second temperature drop of the flow rectifying support plate based on the temperature Pz1 - Pz4 measurement points arranged at the inlet of the flow rectifying support plate 3 and the temperature Pc1 - Pc4 measurement points arranged at the outlet of the flow rectifying support plate 3;

[0074] Determining the second flow resistance of the flow rectifying support plate based on the pressure Tz1 - Tz4 measurement points arranged at the inlet of the flow rectifying support plate 3 and the pressure Tc1 - Tc4 measurement points arranged at the outlet of the flow rectifying support plate 3.

[0075] The flow resistance can be obtained through the difference between two pressures, and the temperature drop can be obtained through the difference between two temperatures. The formulas are not given here. The incoming flow Reynolds number Re obtained through the above formulas is the parameter values at the three Reynolds numbers exemplified in step S1. The air extraction amounts of the anti - icing system in Bo'ai are 100, 230, and 195 g / s respectively. The temperature drops of the gas collecting chamber are 50, 100, and 160 K, the flow resistances of the gas collecting chamber are 5, 15, and 17 kPa, the temperature drops of the support plate are 20, 35, and 42 K, and the flow resistances of the support plate are 13, 55, and 52 kPa. The above parameters correspond to the air extraction amount of the second anti - icing system, the second temperature drop and the second flow resistance of each structure in step S2.

[0076] Finally, in step S3, the initial anti - icing system characteristic model is adjusted according to a preset deviation range.

[0077] In some alternative embodiments, in step S3, the preset deviation range is 10%.

[0078] In some alternative embodiments, in step S3, adjusting the initial anti - icing system characteristic model includes:

[0079] Adjust the flow capacity of the flow resistance unit by adjusting the cross-sectional parameters of the air intake pipe, the throttle holes and exhaust holes of the fairing struts, or by adjusting the turning size parameters of the air intake pipe;

[0080] Adjust the heat transfer capacity of the heat transfer unit by adjusting the heat transfer area and heat conduction area parameters of each structure.

[0081] In this embodiment, in order to make the calculated air intake volume and flow resistance characteristics (the flow resistance of the air collection chamber and the fairing struts) match the test data, it is necessary to adjust the size parameters of the key flow resistance units, generally referring to the units with the most drastic throttling effect. For example, increase or decrease the key parameters such as the flow area and equivalent diameter of some air intake pipes, throttle holes of fairing struts, exhaust holes, and long and narrow channels of the cap, and the turning angle, turning height, and turning radius of the elbow pipe; for some flow resistance units with a larger flow area, there is no need to adjust, because the throttling effect of such units is weaker; in order to make the calculated heat transfer characteristics (the temperature drop of the air collection chamber and the fairing struts) match the test data, it is necessary to adjust the size parameters of the key heat transfer units, generally referring to the units with the most intense heat transfer with the mainstream, such as the heat transfer area, external heat transfer area, and heat conduction area inside and outside the units of the air collection chamber and the mainstream heat transfer side, the front / rear cavity heat transfer units of the fairing struts, and the outer wall of the cap. For some units modeled for natural convection or adiabatic parts, there is no need to adjust, because the heat transfer effect of such units can be ignored.

[0082] For example, for the parameters of the air intake volume of the first anti-icing system, the first temperature drop and the first flow resistance of each structure corresponding to step S1, and the parameters of the air intake volume of the second anti-icing system, the second temperature drop and the second flow resistance of each structure corresponding to step S2 given above, it can be seen that the deviation is relatively large. Therefore, it is necessary to adjust the model and the network. Based on the test data, correct the calculation network, adjust the flow capacity of the units with larger flow resistance, and adjust the heat transfer capacity of the units with stronger heat transfer capacity, so that the deviation from the test results does not exceed 10%. By adjusting the diameter and flow area of the impact holes of the fairing struts (the flow area is reduced to 70% of that before adjustment), adding a turning unit at the root of the fairing strut according to the actual situation, and increasing the heat transfer area of the heat transfer units in the front / rear cavities of the fairing struts and the outer wall of the cap (the heat transfer area is increased by 1.5 times), the comparison results of the air intake volume, temperature drop of the air collection chamber, flow resistance of the air collection chamber, flow resistance of the strut, and temperature drop of the strut of the anti-icing system obtained by the adjusted calculation model and the test are shown in Table 1.

[0083] Table 1 Comparison table of adjusted calculation and whole machine test results

[0084]

[0085] The anti-icing system characteristic model obtained through adjustment can be applied to the subsequent anti-icing effect evaluation.

[0086] In step S4 of this application, the characteristics of the engine anti-icing system in other states are calculated using this model to obtain the anti-icing air extraction volume, the flow and heat transfer characteristics of each component. Then in step S5, an evaluation of the anti-icing effect of the anti-icing system is carried out. Specifically, 5. Based on the corrected calculation model and network, the air extraction volume, the temperature drop in the plenum chamber, the flow resistance in the plenum chamber, the flow resistance of the splitter plate, and the temperature drop of the splitter plate of the anti-icing system in other states are obtained, and the flow and heat transfer characteristics of the anti-icing system under typical working conditions are obtained, as shown in Table 2.

[0087] Table 2 Calculation Results

[0088] Calculation result <![CDATA[R e = 3.0 × 10 7 , ambient temperature -20 °C]]> <![CDATA[R e = 7.0 × 10 7 , ambient temperature -20 °C]]> <![CDATA[R e = 1.25 × 10 8 , ambient temperature -20 °C]]> <![CDATA[Anti-icing system bleed air volume (g / s )]]> 80.0 200.0 205.0 Temperature drop of gas collecting chamber (K) 41.4 81.3 190.0 <![CDATA[Gas collection chamber flow resistance (kP a )]]> 1.2 4.1 4.7 Temperature drop of support plate (K) 20.2 55.4 86.0 <![CDATA[Strut flow resistance (kP a )]]> 10.4 50.3 51.2

[0089] In step S5, an evaluation calculation of the anti-icing effect of the anti-icing system is carried out. The obtained evaluation results are compared with the anti-icing effect verification test of the components. The calculation shows that icing will occur at the leading edge, and the test results are consistent with the calculation results, further verifying the accuracy of the calculation method.

[0090] This application has the following advantages:

[0091] 1. Through the whole-machine test, the cavity temperature and pressure test data of the anti-icing system under conditions close to the actual operation of the engine are obtained, and the anti-icing air extraction volume, flow resistance, and heat transfer characteristics of the anti-icing system are obtained through the test data;

[0092] 2. The existing calculation model is corrected through the whole-machine test data to make the modeling of the anti-icing flow path more realistic and reliable, and a calculation method for the flow and heat transfer characteristics of the anti-icing system based on the whole-machine test that meets the engineering requirements is obtained. At the same time, this method will be verified by the anti-icing effect test at the component level;

[0093] 3. This application adopts a one-dimensional calculation method, which is simple, fast, and the calculation efficiency can be increased by more than 70% compared with the traditional method. It can solve the problems of long cycle, complex program, poor convergence, and large personnel demand brought by three-dimensional numerical simulation;

[0094] 4. The method obtained in this application is simple and easy to operate, has good convergence, and high accuracy;

[0095] 5. This application can quickly and effectively obtain the evaluation results of the anti-icing ability at the initial stage of troubleshooting and multi-scheme design comparison.

[0096] Although this application has been described in detail above with general descriptions and specific implementation examples, based on this application, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of this application all fall within the scope of protection required by this application.

Claims

1. A method for determining the characteristics of an aircraft engine anti-icing system based on whole-machine testing, characterized in that, Including: Step S1: Model the flow path of the anti-icing system with a number of heat exchange units and a number of flow resistance units to obtain an initial anti-icing system characteristic model, and based on the initial anti-icing system characteristic model, obtain the first air extraction volume of the anti-icing system, the first temperature drop and the first flow resistance of each structure at multiple incoming flow Reynolds numbers; Step S2: Conduct an overall aero-engine test under non-icing conditions, and calculate the second air extraction volume of the anti-icing system, the second temperature drop and the second flow resistance of each structure at the multiple incoming flow Reynolds numbers based on the temperature and pressure parameters collected by multiple temperature and pressure sensors arranged on the flow path of the anti-icing system; Step S3: Adjust the initial anti-icing system characteristic model so that the first air extraction volume of the anti-icing system obtained based on the initial anti-icing system characteristic model and the second air extraction volume of the anti-icing system are within a preset deviation range, the first temperature drop of each structure obtained based on the initial anti-icing system characteristic model and the second temperature drop of each structure are within a preset deviation range, and the first flow resistance of each structure obtained based on the initial anti-icing system characteristic model and the second flow resistance of each structure are within a preset deviation range, thereby obtaining an adjusted anti-icing system characteristic model.

2. The method for determining the characteristics of the anti-icing system of an aero-engine based on the overall machine test according to claim 1, wherein After step S3, it further includes: Step S4: Based on the adjusted anti-icing system characteristic model, calculate the anti-icing air extraction volume, the temperature drop and the flow resistance of each structure under multiple working conditions under icing conditions; Step S5: Conduct component-level tests under the multiple working conditions under icing conditions to verify the adjusted anti-icing system characteristic model.

3. The method for determining the characteristics of an aeroengine anti-icing system based on the overall machine test according to claim 1, wherein In step S1, the first temperature drop and the first flow resistance of each structure include: the first temperature drop and the first flow resistance of the air collection chamber, the first temperature drop and the first flow resistance of each fairing strut; in step S2, the second temperature drop and the second flow resistance of each structure include: the second temperature drop and the second flow resistance of the air collection chamber, the second temperature drop and the second flow resistance of each fairing strut.

4. The method for determining the characteristics of the anti-icing system of an aero-engine based on the overall engine test according to claim 3, wherein, In step S2, the multiple temperature and pressure sensors arranged on the flow path of the anti-icing system include: Arranging total temperature Tt1 and static pressure Ps1 measurement points at a certain cross-section of the air intake pipe upstream of the control accessory (7); Arranging total temperature Tt2, total pressure Pt2 and static pressure Ps2 measurement points at a certain cross-section of the air intake pipe downstream of the control accessory (7); Arranging temperature Tj1 and pressure Pj1 measurement points at the hot air inlet of the air collection chamber (2), and arranging temperature Tj2 and pressure Pj2 measurement points at the farthest point of the hot air travel distance from the hot air inlet of the air collection chamber (2); Arranging pressure Tz1 - Tz4 and temperature Pz1 - Pz4 measurement points at the inlet of the fairing strut (3), and arranging pressure Tc1 - Tc4 and temperature Pc1 - Pc4 measurement points at the outlet of the fairing strut (3); Wherein, the high-pressure compressor (5) is connected to the anti-icing system air extraction seat (1) through an air intake pipe (6), the anti-icing system air extraction seat (1) is connected to the hot air inlet of the air collection chamber (2), the air collection chamber (2) is an annular chamber, and is connected to a cap (4) located at the center of the annular chamber through a number of fairing struts (3), and the control accessory (7) is arranged on the air intake pipe (6).

5. The method for determining the characteristics of the anti-icing system of an aero-engine based on the overall machine test according to claim 4, characterized in that, In step S2, determining the second air extraction volume of the anti-icing system includes: Obtaining the ideal flow rate of the anti-icing system; Determine the flow coefficient based on the total static pressure ratio of the air duct (6) in front of the air extraction seat (1) of the anti-icing system in the anti-icing system, wherein the relationship between the total static pressure ratio and the flow coefficient is obtained through a flow calibration test; Based on the ideal flow rate and the flow coefficient, determine the air extraction volume of the second anti-icing system.

6. The method for determining the characteristics of an aero-engine anti-icing system based on the overall machine test according to claim 4, wherein, In step S2, determining the second temperature drop and the second flow resistance of each structure includes: Based on the temperature Tj1 measurement point arranged at the hot air inlet of the air collecting chamber (2) and the temperature Tj2 measurement point arranged at the farthest point of the hot air travel distance from the hot air inlet of the air collecting chamber (2), determine the second temperature drop of the air collecting chamber; Based on the pressure Pj1 measurement point arranged at the hot air inlet of the air collecting chamber (2) and the pressure Pj2 measurement point arranged at the farthest point of the hot air travel distance from the hot air inlet of the air collecting chamber (2), determine the second flow resistance of the air collecting chamber; Based on the temperature Pz1 - Pz4 measurement points arranged at the inlet of the flow rectifying support plate (3) and the temperature Pc1 - Pc4 measurement points arranged at the outlet of the flow rectifying support plate (3), determine the second temperature drop of the flow rectifying support plate; Based on the pressure Tz1 - Tz4 measurement points arranged at the inlet of the flow rectifying support plate (3) and the pressure Tc1 - Tc4 measurement points arranged at the outlet of the flow rectifying support plate (3), determine the second flow resistance of the flow rectifying support plate.

7. The method for determining the characteristics of the anti-icing system of an aero-engine based on the overall machine test according to claim 1, characterized in that In step S3, the preset deviation range is 10%.

8. The method for determining the characteristics of an aero-engine anti-icing system based on the overall engine test according to claim 1, characterized in that, In step S3, adjusting the initial anti-icing system characteristic model includes: Adjust the flow capacity of the flow resistance unit by adjusting the cross-sectional parameters of the throttle holes and exhaust holes of the air duct and the flow rectifying support plate, or by adjusting the turning dimension parameters of the air duct; Adjust the heat exchange capacity of the heat exchange unit by adjusting the heat exchange area and heat conduction area parameters of each structure.

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