CN118424721B - Aeroengine test run performance adjusting method - Google Patents

Abstract

The invention discloses an aeroengine test performance adjusting method in the technical field of aeroengine test, which comprises the steps of pre-testing temperature during a test vehicle to evaluate engine power level during test, calculating each parameter of the engine during test according to the power level of the engine, predicting the difference between power turbine shaft torque and turbine indication temperature and test limit value during test, selecting at least one of an air inlet cooling method and an air inlet flow control method to adjust turbine shaft torque, and selecting at least one of a guide vane adjusting method, a guide area adjusting method, an outlet bleed air adjusting method, a motor loading power adjusting method and an anti-icing bleed air adjusting method to adjust turbine indication temperature, so that each parameter of the engine during test reaches the limit value, avoiding that partial parameter of the engine seriously exceeds the maximum limit value or test specified value, and simultaneously avoiding multiple test runs or high-altitude test, and saving economic cost and time cost of test.

Description

A method for adjusting performance of aircraft engine test run

Technical Field

The invention relates to the technical field of aircraft engine test run, and in particular to an aircraft engine test run performance adjustment method.

Background Art

During the development process of aircraft engines, the aircraft engines are required to undergo 150-hour endurance tests, first overhaul life tests and dynamic stress measurements.

The main purpose of the 150-hour endurance test is to test the operating limits of the engine. Especially for civil aviation engines, when the engine is running at rated power, the main rotor speed, turbine indicated temperature and power turbine shaft torque are required to reach the maximum limit values of the state, namely the "three red lines".

The main purpose of the first overhaul life test is to assess the engine's intended life capability. When the engine runs to the specified state according to the test spectrum, the main rotor speed and turbine indicated temperature should meet the corresponding test specified values.

Dynamic stress measurement verifies the stress level of the engine over the entire speed range, requiring the main rotor speed to reach the highest transient speed or even requiring the speed to be further increased.

The main rotor speed, turbine indicated temperature and power turbine shaft torque are important operating parameters of aviation turboshaft turboprop engines. The main rotor speed affects the centrifugal load borne by the engine's rotating parts, the turbine indicated temperature affects the thermal load borne by the hot end components, and the power turbine shaft torque affects the shear load of the power turbine shaft and its supporting bearings. In order to ensure that the engine operates within an acceptable range, the designer will specify the maximum limit values of the main rotor speed, turbine indicated temperature and power turbine shaft torque at different rated power states.

During the ground test, due to the limitations of component matching, atmospheric conditions and other factors, it is difficult for the engine's main rotor speed, turbine indicated temperature and power turbine shaft torque to reach the maximum limit value or test specified value at the same time. When the speed is pushed up to the highest transient speed or even higher speed according to the dynamic stress measurement requirements, it is very likely that the turbine indicated temperature will seriously exceed the maximum limit value. The main reasons for the above problems are:

1) The higher the atmospheric temperature, the harder it is to compress the air, the compressor flow and pressure ratio both decrease, the lower the engine power, the lower the torque of the power turbine output shaft, and it is more difficult to reach the torque limit value; and for a turboshaft turboprop engine with a reducer at the power output end, its torque limit value is generally determined by the strength limit of the reducer. If the atmospheric temperature is too low, the torque of the power turbine output shaft will be too high, affecting the operation of the reducer;

2) The aerodynamic matching of components of different engines is inconsistent. Any parameter of the main rotor speed or turbine indicated temperature may reach the maximum limit value or test specified value in advance, while the other parameter is lower than the maximum limit value or test specified value. Even for the same type of engine, there may be differences due to processing dispersion;

3) Due to the influence of engine characteristics, when the atmospheric temperature changes, the corresponding relationship between the main rotor speed and the turbine indicated temperature is likely to change;

4) During the 150-hour endurance test, multiple rated power states such as maximum continuous, takeoff, and emergency need to be verified. The maximum limit values corresponding to each rated power state are different, and the parameters that reach the maximum limit value in advance for each rated power state may also be different;

5) The specified conditions of the first overhaul life test are generally based on the working conditions at a specific temperature and altitude. The corresponding relationship between the main rotor speed and the turbine indicated temperature is often quite different from the ground vehicle test.

6) The maximum transient speed takes into account that when the engine is quickly pushed up to the highest state, the speed may exceed the corresponding maximum limit value. At this time, due to the influence of thermal hysteresis, the turbine indicated temperature exceeds the maximum limit value by a small margin. However, dynamic stress measurement requires a slow increase in speed. If the test speed is required to be higher than the maximum transient speed, the turbine indicated temperature will seriously exceed the maximum limit value.

At present, the methods used to solve the above problems are:

1) Arrange two or more test runs to test the maximum limit values of the main rotor speed, turbine indicated temperature and power turbine shaft torque respectively, which has a high cycle and cost;

2) When one of the parameters reaches the maximum limit value or the test specified value in advance, the engine state is continuously pushed up, causing some engine parameters to seriously exceed the maximum limit value or the test specified value;

3) Carry out tests on an altitude test bench and select reasonable atmospheric conditions so that the main rotor speed, turbine indicated temperature and power turbine shaft torque simultaneously achieve the maximum limit value or test specified value. However, the test cost of the altitude test bench is very high.

Based on this, the present invention designs an aircraft engine test performance adjustment method to solve the above problems.

Summary of the invention

To achieve the above object, the present invention provides the following technical solution: an aircraft engine test performance adjustment method, the test performance adjustment method comprising the following steps:

Step 1: Ground test to obtain the performance parameters of the engine at a typical speed state, including speed, power, fuel flow, compressor outlet temperature, gas turbine outlet temperature and compressor pressure ratio;

Step 2: Establish an overall engine performance simulation model based on the performance parameters of the engine at a typical speed state;

Step 3: Predict the atmospheric temperature variation range during the test run, input the predicted atmospheric temperature and the main rotor speed limit value into the engine overall performance simulation model, the main rotor speed includes the gas generator speed and the power turbine speed, calculate the engine power level during the test run in the predicted atmospheric temperature range, and calculate the power turbine shaft torque prediction value and turbine indicated temperature prediction value during the test run based on the engine power level;

Step 4, through experiments or simulation calculations, obtain the adjustment amounts of the power turbine shaft torque adjustment method and the turbine indicated temperature adjustment method for the power turbine shaft torque and the turbine indicated temperature at the same speed, and select the optimal adjustment scheme;

Step five, combine the adjustment plan with the test process so that the main rotor speed, turbine indicated temperature and power turbine shaft torque all reach the limit values during the test.

As a further scheme of the present invention, in step four, the turbine shaft torque regulation method includes at least one of an intake cooling method and an intake flow control method; the intake cooling method is to use a cooling device to be arranged in the main intake path or/and the intake bypass of the engine to cool the air in the main intake path to increase the engine turbine shaft torque; the intake flow control method is to use a flow channel blocking device to be arranged in the main intake path or the intake port of the main intake path to reduce the air pressure at the engine inlet to reduce the engine turbine shaft torque.

As a further solution of the present invention, in step 4, the turbine indicated temperature adjustment method includes at least one of a guide vane adjustment method, a guide valve area adjustment method, an outlet bleed air adjustment method, a motor load power adjustment method and an anti-icing bleed air adjustment method; the guide vane adjustment method is to control the guide vane angle at the engine compressor inlet to control the compression capacity of the compressor to adjust the turbine indicated temperature; the guide valve area adjustment method is to adjust the gas turbine guide valve or the power turbine guide valve area to control the expansion ratio distribution between the gas turbine and the power turbine to adjust the turbine indicated temperature; the outlet bleed air adjustment method is to control the opening ratio of the compressor outlet bleed air valve to control the gas flow through the gas turbine to adjust the turbine indicated temperature; the motor load power adjustment method is to extract power from the compressor end for power generation, increase the power consumption of the compressor to increase the turbine indicated temperature; the anti-icing bleed air adjustment method is to open the anti-icing bleed air to provide hot air for the anti-icing part of the engine, increase the engine inlet temperature, and generate temperature distortion at the engine inlet to increase the turbine indicated temperature.

As a further solution of the present invention, the cooling device includes an air cooling device and/or a water spraying device, which is used to cool the air in the main air intake path.

As a further solution of the present invention, the water spraying device should use soft water when working, and the content of calcium salt and magnesium salt should be 1.0-20 mg/L.

As a further solution of the present invention, the flow channel blocking device adopts a plate with a through hole in the middle and/or a metal grid and/or an intake distortion plate.

As a further solution of the present invention, in step 2, the process of establishing the performance model of the engine is S1, calculating the difference between the performance parameters of the engine at a typical speed state and the calculation results of the overall simulation model, and determining the correction amount of the characteristic diagram parameters of the components such as the compressor, the gas turbine and the power turbine;

S2, modifying the overall performance simulation model established based on the component characteristic diagram to obtain an overall performance simulation model suitable for the engine.

As a further solution of the present invention, in step three, the atmospheric temperature variation range during the test run is predicted based on the climate conditions of previous years or with reference to the weather forecast of the meteorological station, and the tolerance is taken into account when predicting the atmospheric temperature variation range during the test run.

As a further solution of the present invention, in step 4, during the test or simulation calculation, it is also necessary to derive the influence of the power turbine shaft torque adjustment method and the turbine indicated temperature adjustment method on the engine surge margin.

As a further solution of the present invention, when the engine turbine indicated temperature is adjusted by the guide vane adjustment method, an electronic controller on the engine for controlling the guide vane angle is used to pre-set the guide vane angle at a typical speed, and the angles corresponding to other speeds are automatically interpolated based on the angle at the typical speed.

The present invention has the following beneficial effects:

This method estimates the atmospheric temperature during the test run and infers the engine power level during the test run through a modified engine overall performance simulation model, thereby evaluating the power turbine shaft torque and turbine indicated temperature during the test run. Then, based on the difference between the predicted result and the limit value to be reached during the test run, a suitable power turbine shaft torque adjustment method and turbine indicated temperature adjustment method are selected. During the test run, the power turbine shaft torque and turbine indicated temperature are adjusted through a pre-established plan so that the power turbine shaft torque and turbine indicated temperature reach the limit value, thereby preventing some engine parameters from seriously exceeding the maximum limit value or the test specified value, and also avoiding multiple test runs or high-altitude platform tests, thereby saving the economic cost and time cost of the test run.

In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

FIG. 1 is a flow chart of the invented method for adjusting the performance of an aircraft engine during test run.

FIG. 2 is a schematic diagram of an exemplary structure of the present invention.

Figure 3 is a gas generator speed curve for a turboshaft engine during a 150-hour endurance test.

Figure 4 is a turbine indicated temperature curve of a turboshaft engine during a 150-hour endurance test.

Figure 5 is the torque curve of the turbine shaft of a turboshaft engine during a 150-hour endurance test.

Legend:

1. Flow channel blocking device; 2. Main air intake path; 3. Hydraulic dynamometer; 4. Volute; 5. Air cooling device; 6. Water spray device; 7. First air intake bypass; 8. Second air intake bypass; 9. Guide vane; 10. Electronic controller; 11. Anti-icing air bleed; 12. Compressor outlet air bleed valve; 13. Gas turbine guide vane; 14. Power turbine guide vane.

DETAILED DESCRIPTION

The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

Please refer to Figures 1-5. The present invention provides a technical solution: an aircraft engine test performance adjustment method, the test performance adjustment method comprises the following steps:

Step 1: Ground test to obtain the performance parameters of the engine at a typical speed state, including speed, power, fuel flow, compressor outlet temperature, gas turbine outlet temperature and compressor pressure ratio;

Step 2: Establish an overall engine performance simulation model based on the performance parameters of the engine at a typical speed state;

Step 3: Predict the atmospheric temperature variation range during the test run, input the predicted atmospheric temperature and the main rotor speed limit value into the engine overall performance simulation model, the main rotor speed includes the gas generator speed and the power turbine speed, calculate the engine power level during the test run in the predicted atmospheric temperature range, and calculate the power turbine shaft torque prediction value and turbine indicated temperature prediction value during the test run based on the engine power level;

Step 4, through experiments or simulation calculations, obtain the adjustment amounts of the power turbine shaft torque adjustment method and the turbine indicated temperature adjustment method for the power turbine shaft torque and the turbine indicated temperature at the same speed, and select the optimal adjustment scheme;

Step five, combine the adjustment plan with the test process so that the main rotor speed, turbine indicated temperature and power turbine shaft torque all reach the limit values during the test.

During the test run, the power turbine shaft torque and turbine indicated temperature are adjusted through a pre-established plan so that they reach the limit values. There is no need to push up the engine state to cause one or more parameters to exceed the limit values. The test run is safer and avoids conducting two or more test runs, effectively shortening the test cycle and cost.

Specifically, in step one, the typical converted speed can be 0.9, 0.92, 0.95, 0.968, 0.988 and 1.0, etc. The engine performance parameters are easily affected by atmospheric conditions, but by complying with similar conversion criteria, they can generally be converted to standard atmospheric conditions to facilitate the evaluation of engine performance. The typical converted speed represents the typical converted working state of the engine. The performance parameters of each component of the engine are closely related to the speed. The performance data corresponding to the typical converted speed can provide a basis for model correction.

Specifically, in step 2, the process of establishing the overall performance simulation model of the engine is as follows:

According to the difference between the actual performance parameters obtained during the engine ground test in step one and the calculation results of the overall simulation model, the correction amount of the characteristic diagram parameters of components such as the compressor, gas turbine and power turbine is determined, and the overall performance simulation model established based on the component characteristic diagram is corrected to obtain an overall performance simulation model suitable for the engine, so that the subsequent predictions and calculation results based on the engine overall performance simulation model are closer to the actual results.

Specifically, in step 2, the method for establishing the overall performance simulation model of the engine is:

According to the aerodynamic thermodynamic characteristics of the engine and the parameter items of the characteristic diagrams of each component, and then based on the flow balance and power balance limitations between the components when the engine works together, a group of joint working control equations are constructed, including the flow balance between the compressor and the gas turbine, the power balance between the compressor rotor and the gas turbine rotor, the flow balance between the gas turbine and the power turbine, the flow balance between the power turbine and the tail jet, and then an overall engine performance simulation model is established.

Specifically, in step three, the atmospheric temperature change range during the test run is predicted based on the climatic conditions of previous years or with reference to the weather forecast of the meteorological station. When predicting the atmospheric temperature change range during the test run, in order to avoid deviations between the predicted climate and the actual weather, a certain tolerance can be considered to predict a larger climate change range, and then the highest temperature and the lowest temperature in the predicted range are selected as input conditions for simulation, and the predicted values of the power turbine shaft torque and the turbine indicated temperature are calculated when the main rotor speed of the engine test reaches the limit value.

Specifically, in step three, the main rotor speed includes the gas generator speed and the power turbine speed. Current turboshaft engines generally use a free-style power turbine, that is, there is no mechanical connection between the power turbine rotor and the gas generator, and there is only aerodynamic interaction. The power turbine uses constant speed control, and the speed control target can be adjusted to meet the limit value requirements. However, it is necessary to consider the impact of the power turbine speed adjustment on the gas turbine outlet temperature, power and torque at the same gas generator speed.

Specifically, in step 4, the turbine shaft torque adjustment method includes an intake air cooling method and an intake air flow control method, and the turbine indicated temperature adjustment method includes a guide vane adjustment method, a guide vane area adjustment method, an outlet bleed air adjustment method, a motor load power adjustment method, and an anti-icing bleed air adjustment method;

The higher the atmospheric temperature, the harder it is to compress the air, the compressor flow and pressure ratio both decrease, the lower the engine power, the lower the torque of the power turbine output shaft. The actual atmospheric temperature of the ground vehicle is often higher, so the torque of the power turbine shaft is often difficult to reach the limit value during the test run of the ground vehicle. The intake cooling method is to use a cooling device to be set on the engine's intake main path 2 or/and intake bypass to cool the air in the intake main path 2 to increase the engine turbine shaft torque;

The intake flow control method is to use a flow channel blocking device 1 to be set in the intake main path 2 or the intake port of the intake main path 2, which can cause pressure loss of the air flow entering the engine, reduce the air pressure at the engine inlet, and the air pressure after being compressed by the compressor will also be reduced, affecting the working ability of the gas on the power turbine. At the same time, the reduction in pressure will also reduce the air density, thereby reducing the air flow entering the engine, resulting in a reduction in engine power, so as to reduce the engine turbine shaft torque;

The guide vane adjustment method is to control the angle of the guide vane 9 at the inlet of the engine compressor. The larger the angle of the guide vane 9, the higher the compression capacity of the compressor, and the higher the power consumption of the compressor, so that the gas turbine needs more fuel and a higher turbine inlet temperature to drive the compressor, thereby increasing the turbine indicated temperature corresponding to the same gas generator speed, and vice versa, the turbine indicated temperature decreases, so as to adjust the turbine indicated temperature;

The guide vane area adjustment method is to adjust the area of the gas turbine guide vane 13 or the power turbine guide vane 14. By increasing the area of the gas turbine guide vane 13 or decreasing the area of the power turbine guide vane 14, the expansion ratio of the gas turbine will be reduced, so that the gas turbine needs more fuel and a higher turbine inlet temperature to drive the compressor, thereby increasing the turbine indicated temperature.

The outlet bleed air regulation method is to control the opening ratio of the compressor outlet bleed air valve 12, increase the compressor outlet bleed air flow, which will reduce the gas flow through the gas turbine. The engine increases the fuel flow and the turbine inlet temperature to make the power generated by the gas turbine meet the needs of the compressor, so as to increase the turbine indicated temperature;

The motor loading power regulation method is to extract power from the compressor end for power generation, increase the power consumption of the compressor, require the gas turbine to generate more power, and increase the fuel flow, turbine inlet temperature and turbine indicated temperature;

The anti-icing bleed air adjustment method is to open the anti-icing bleed air 11, which, on the one hand, increases the engine inlet temperature, making it difficult to compress the air, and on the other hand, causes temperature distortion at the engine inlet, which reduces the compressor compression efficiency, increases the compressor power consumption, requires the gas turbine to generate more power, and increases the fuel flow, turbine inlet temperature and turbine indicated temperature;

Through simulation calculation or experiment, calculate the influence of changes in intake temperature, guide vane 9 angle, burner turbine guide vane area, power turbine guide vane 14 area, compressor outlet bleed air valve 12 opening ratio, motor loading power and anti-icing bleed air 11 on turbine indicated temperature, torque and surge margin at the same speed, record the corresponding change relationship, and determine the appropriate adjustment plan.

Figure 2 shows an example of a cooling device. In this example, the cooling device includes an air cooling device 5 and/or a water spray device 6. The air cooling device 5 and the water spray device 6 are respectively installed on the first air intake bypass 7 and the second air intake bypass 8. The first air intake bypass 7 and the second air intake bypass 8 are both connected to the main air intake path 2. The air in the first air intake bypass 7 and the second air intake bypass 8 is cooled by the air cooling device 5 and/or the water spray device 6, and the cooled gas enters the main air intake path 2 to mix with the air in the main air intake path 2 and then cool it down to increase the torque of the power turbine shaft.

Furthermore, due to the high temperature of the working parts of the engine, when the calcium and magnesium compound content in the cooling water sprayed by the water spray device 6 is high, it will be adsorbed on the surface of the flow path after passing through the high-temperature parts, thereby affecting the engine performance. Therefore, the water spray device 6 should use soft water when working, and the calcium and magnesium salt content should be 1.0~20mg/L.

Furthermore, when the water spray device 6 is used to cool the main intake path 2, the water spray volume should not exceed 4% of the air flow rate. When the water spray volume exceeds 4% of the air flow rate, it may cause the engine to surge during acceleration. Therefore, before the test, the performance model should be used to calculate the engine's air flow rate to avoid excessive water spray volume.

As shown in Figure 2, in this example, a volute 4 is installed at the engine inlet, and the main air intake path 2 is installed at the axial inlet of the volute 4. Generally, due to the limitations of the test bench size and the rotor dynamics characteristics, the axial distance between the turboshaft turboprop engine with pre-power output and the hydraulic dynamometer 3 is relatively short, which may affect the installation of the cooling device and the flow channel blocking device 1. By installing the volute 4 at the engine air inlet, the main air intake path 2 and the hydraulic dynamometer 3 can be staggered in the radial direction, thereby providing space for the installation of the cooling device and the flow channel blocking device 1.

The air cooling device 5 and the water spraying device 6 are both conventional technical means in the art and will not be described in detail here.

Figure 2 shows an example of a flow channel blocking device 1. In this example, the flow channel blocking device 1 is installed at the inlet end of the main air intake path 2 to block the inlet end of the main air intake path 2, causing pressure loss in the air flow entering the engine, thereby reducing the air pressure at the engine inlet, thereby achieving the effect of reducing the torque of the power turbine shaft.

The flow channel blocking device 1 can be a plate with a through hole in the middle, a metal grid, or an intake distortion plate. The present application does not impose any restrictions on this, as long as it can cause pressure loss in the air flow entering the engine.

In this embodiment, when the engine turbine indicated temperature is adjusted by the guide vane adjustment method, the electronic controller 10 on the engine for controlling the angle of the guide vane 9 can be used to pre-set the angle of the guide vane 9 at a typical speed, and the angles corresponding to other speeds are automatically interpolated based on the angle of the typical speed.

The following is an example of adjusting various parameters of an aircraft engine during a 150-hour endurance test using this method;

1) Carry out ground test to obtain the performance parameters of the engine at typical speed. According to the difference between the performance parameters at typical speed and the calculation results of the overall simulation model (as shown in Table 1), determine the correction amount of the characteristic diagram parameters of the compressor, gas turbine and power turbine (as shown in Table 2), and correct the overall performance simulation model established based on the component characteristic diagram, so as to obtain the overall performance simulation model suitable for the engine.

Table 1 Differences between actual engine performance parameters and calculation results of the overall simulation model

Table 2 Component characteristic diagram correction

2) According to the engine development work schedule, the 150-hour endurance test is scheduled to be carried out in June. Based on the climate conditions of previous years and taking into account the tolerance of ±3°C, the atmospheric temperature during the test is predicted to be about 25-35°C. The performance parameters at atmospheric temperatures of 25°C and 35°C are evaluated using the revised overall performance simulation model, as shown in Table 3. Since the motor needs to be loaded throughout the endurance test, the data in the table take into account the impact of motor loading. It can be seen from the table that when the speed limit value is reached, the torque of the power turbine shaft of the engine in each state basically meets the requirements when the atmospheric temperature is 25°C, but the corresponding turbine indicated temperature is relatively high. If the turbine indicated temperature is reduced by reducing the angle of the guide vane, the corresponding torque will also decrease. There is no obvious margin for the torque relative to the limit value. During the test, the parameters will fluctuate due to the influence of the control accuracy, and it is very likely that the torque will be lower than the torque limit value. When the atmospheric temperature is 35°C, the torque of the engine in each state obviously cannot meet the limit value requirements. According to the evaluation of the engine intake flow rate, the air cooling device 5 cannot fully meet the cooling demand due to the power load limitation. A water spray device 6 is established to ensure that the engine torque meets the limit value requirements during the high temperature test.

Table 3 Differences in relative limit values of engine evaluation parameters (speed limit value status)

3) Using the whole machine performance model and the previous debugging test comparison data, the influence of different adjustment measures on the engine performance is summarized, as shown in Table 4. Since the engine is equipped with an angle-adjustable guide vane 9 at the compressor inlet, when the torque meets the limit value requirements, it is possible to give priority to adjusting the turbine indicated temperature by adjusting the angle of the guide vane 9.

Table 4 Effects of adjustment measures on engine performance parameters

4) According to Table 3 and Table 4, determine the test adjustment scheme, as shown in Table 5. As shown in Table 3, since the relative limit value of the turbine indicated temperature in each state is 14 to 24 °C higher, it is preferred to reduce the angle of the guide vane. However, the reduction of the guide vane will cause the torque of the power turbine shaft to decrease. Therefore, it is necessary to turn on the air cooling device to reduce the intake temperature and increase the torque. However, due to the power load limit, the intake temperature can only drop by 3 °C at most. When the atmospheric temperature reaches 35 °C, soft water must be injected into the engine inlet through the water spray device to increase the torque. Before the test, the performance model should be used to calculate the air flow of the engine to avoid excessive water spray. After water spraying, the turbine indicated temperature will also decrease. Therefore, the influence of the guide vane angle and the proportion of water spraying should be comprehensively considered to reasonably determine the adjustment parameters. After adjustment, the engine parameters can meet the limit value requirements at the same time. The turbine indicated temperature is 3.5 to 5°C higher than the limit value, and the power turbine shaft torque is 4.1 to 7.9 N·m higher than the limit value. This can not only prevent the engine from being in a state of excessive testing, but also ensure that various parameters are always above the limit value under the influence of control accuracy to meet the test requirements.

Table 5 Differences in relative limit values of engine parameters after adjustment (speed limit value status)

5) The method provided by the present invention successfully completed a 150-hour endurance test, and the test curves of a certain stage are shown in Figures 3 to 5.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. An aero-engine test performance adjustment method, characterized in that the test performance adjustment method comprises the following steps: Step 1: Ground test to obtain the performance parameters of the engine at a typical speed state, including speed, power, fuel flow, compressor outlet temperature, gas turbine outlet temperature and compressor pressure ratio; Step 2: Establish an overall engine performance simulation model based on the performance parameters of the engine at a typical speed state; Step 3: Predict the atmospheric temperature variation range during the test run, input the predicted atmospheric temperature and the main rotor speed limit value into the engine overall performance simulation model, the main rotor speed includes the gas generator speed and the power turbine speed, calculate the engine power level during the test run in the predicted atmospheric temperature range, and calculate the power turbine shaft torque prediction value and turbine indicated temperature prediction value during the test run based on the engine power level; Step 4, through experiments or simulation calculations, obtain the adjustment amounts of the power turbine shaft torque adjustment method and the turbine indicated temperature adjustment method for the power turbine shaft torque and the turbine indicated temperature at the same speed, and select the optimal adjustment scheme; Step five, combine the adjustment plan with the test process so that the main rotor speed, turbine indicated temperature and power turbine shaft torque all reach the limit values during the test. 2. The method for adjusting the performance of an aircraft engine test run according to claim 1, wherein: in step 2, the engine performance model establishment process is S1, calculate the difference between the performance parameters of the typical engine speed state and the calculation results of the overall simulation model, and determine the correction amount of the characteristic diagram parameters of the compressor, gas turbine and power turbine components; S2, modifying the overall performance simulation model established based on the component characteristic diagram to obtain an overall performance simulation model suitable for the engine. 3. The method for adjusting the performance of an aircraft engine test run according to claim 1 is characterized in that: in step 3, the atmospheric temperature variation range during the test run is predicted based on the climate conditions of previous years or with reference to the weather forecast of the meteorological station, and the tolerance is taken into account when predicting the atmospheric temperature variation range during the test run. 4. The method for adjusting the performance of an aircraft engine test run according to claim 1, characterized in that: in step 4, the turbine shaft torque adjustment method includes at least one of an intake air cooling method and an intake air flow control method; The intake air cooling method is to use a cooling device to be arranged on the main intake path or/and the intake bypass path of the engine to cool the air in the main intake path to increase the torque of the engine turbine shaft; The intake flow control method is to use a flow channel blocking device set in the main intake path or the intake port of the main intake path to reduce the air pressure at the engine inlet to reduce the engine turbine shaft torque. 5. The method for adjusting the performance of an aircraft engine test run according to claim 1, characterized in that: in step 4, the turbine indicated temperature adjustment method includes at least one of a guide vane adjustment method, a guide vane area adjustment method, an outlet bleed air adjustment method, a motor load power adjustment method, and an anti-icing bleed air adjustment method; The guide vane adjustment method is to control the guide vane angle at the engine compressor inlet to control the compression capacity of the compressor to adjust the turbine indicated temperature; The guide vane area adjustment method is to adjust the area of the gas turbine guide vane or the power turbine guide vane to control the expansion ratio distribution between the gas turbine and the power turbine to adjust the turbine indicated temperature; The outlet bleed air regulation method is to control the opening ratio of the compressor outlet bleed air valve to control the gas flow through the gas turbine to adjust the turbine indicated temperature; The motor loading power regulation method is to extract power from the compressor end for power generation, increase the power consumption of the compressor, and increase the turbine indicated temperature; The anti-icing air bleed adjustment method is to open the anti-icing air bleed to provide hot air to the anti-icing part of the engine, so that the engine inlet temperature increases and the engine inlet generates temperature distortion to increase the turbine indicated temperature. 6. An aircraft engine test performance adjustment method according to claim 4, characterized in that: the cooling device includes an air cooling device and/or a water spraying device for cooling the air in the main air intake path. 7. An aircraft engine test performance adjustment method according to claim 6, characterized in that the water spraying device uses soft water when working, and the content of calcium salt and magnesium salt is 1.0-20 mg/L. 8. An aircraft engine test performance adjustment method according to claim 4, characterized in that: the flow channel blocking device adopts a plate with a through hole in the middle or/and a metal grid or/and an intake distortion plate. 9. An aircraft engine test performance adjustment method according to claim 1, characterized in that: in step 4, during the test or simulation calculation, it is also necessary to obtain the influence of the power turbine shaft torque adjustment method and the turbine indicated temperature adjustment method on the engine surge margin. 10. The method for adjusting the performance of an aircraft engine test run according to claim 5 is characterized in that: when adjusting the engine turbine indicated temperature by the guide vane adjustment method, an electronic controller on the engine for controlling the guide vane angle is used to pre-set the guide vane angle at a typical speed, and the angles corresponding to other speeds are automatically interpolated based on the angle at the typical speed.