Main fuel control design method for engine in slow vehicle state based on flight-engine matching requirement

Abstract

The invention belongs to the technical field of engine control design, and particularly relates to a slow state engine fuel control design method based on flight-engine matching requirements, a ground slow state and an air slow state are distinguished, main fuel control design is carried out respectively, and on the basis that the slow thrust requirement of a typical point is met and normal work of an engine is guaranteed, fuel control design is carried out. The air entraining pressure requirement of an aircraft cockpit, the flow matching requirement of an aircraft air inlet channel and an engine air inlet channel and the stable working performance requirement of an engine under the full envelope service condition are effectively met, and the method is simple and easy to implement.

Description

Technical Field

[0001] This application belongs to the technical field of engine control design, and particularly relates to a design method for engine fuel control in the idle state based on the requirements of engine-aircraft matching. Background Art

[0002] When an aircraft performs actions such as level flight deceleration, high-altitude gliding, and maneuvering flight, the engine is often in the idle state. The idle state is one of the most important operating states of the engine, and the rationality of its design will not only affect the economy, reliability, and safety of the engine, but also affect the safety and maneuverability of the aircraft.

[0003] Currently, for the design of the main fuel flow control in the engine idle state, it is mostly based on the typical point idle thrust requirements given by the user to ensure the normal operation of the engine. The relationship curve of the relative physical speed of the high-pressure rotor in the engine idle state with respect to the engine inlet temperature is calculated and given. The higher value is selected from the fuel supply required to maintain the relative physical speed of the high-pressure rotor and the minimum fuel flow in the idle state as the control of the main fuel flow in the engine idle state, and it is verified through bench and flight tests, and finally the control of the main fuel flow in the engine idle state is determined through iteration. This technical solution is simple and easy to implement.

[0004] Within the full envelope, at different altitudes and Mach numbers, the variation range of the total inlet temperature and total inlet pressure of the engine is very large. Under different total inlet pressures of the engine, different relative converted speeds of the low-pressure rotor are required to ensure the stable operating performance of the axial force of the engine, the sealing of each cavity, the overall vibration, and the combustion in the combustion chamber. The design of the main fuel flow control in the engine idle state obtained by the existing method cannot ensure that the aircraft cabin pressure is maintained within the ideal range under the full envelope operating conditions, and there will be a situation where, under supersonic maneuvering flight conditions, when the engine is operating in the intermediate and above states, the inlet air flow is large, and when the engine throttle lever is quickly pulled to the idle state, the inlet air flow of the engine quickly decreases, while the air flow of the aircraft inlet duct is still large, and the flow mismatch causes surging of the aircraft inlet duct and the engine, seriously affecting flight safety.

[0005] In view of the existence of the above technical defects, this application is proposed. Summary of the Invention

[0006] The purpose of this application is to provide a design method for the main fuel control of an engine in the idle state based on the requirements of engine-aircraft matching, so as to overcome or mitigate at least one aspect of the known technical defects.

[0007] The technical solution of this application is as follows:

[0008] A design method for engine fuel control in the idle state based on the requirements of engine-aircraft matching includes a design method for the main fuel control of an engine in the ground idle state and a design method for the main fuel control of an engine in the air idle state;

[0009] Design method for main fuel control of engine in ground idle state, including:

[0010] S11. Determine the relative corrected speed n1r_grd_0 of the low-pressure rotor of the engine in the ground idle state at standard sea level;

[0011] S12. Refer to the relative corrected speed n1r_grd_0 of the low-pressure rotor of the engine in the ground idle state at standard sea level, and determine the relative corrected speed n1r_grd_1 of the low-pressure rotor required to ensure the stable operating performance of the engine under different total inlet pressures Pt2 of the engine in the ground idle state;

[0012] S13. Calculate the minimum fuel flow rate Wf_grd_min for stable combustion in the ground idle state;

[0013] S14. Select the higher value from the fuel supply required to maintain n1r_grd_1 and Wf_grd_min as the main fuel control of the engine in the ground idle state;

[0014] Design method for main fuel control of engine in in-flight idle state, including:

[0015] S21. Determine the minimum corrected speed n1r_air_1 of the low-pressure rotor of the engine required to meet the demand of the aircraft cabin bleed air pressure Pt27 under different total inlet pressures Pt2 of the engine;

[0016] S22. Refer to the minimum corrected speed n1r_air_1 of the low-pressure rotor of the engine required to meet the demand of the aircraft cabin bleed air pressure Pt27 under different total inlet pressures Pt2 of the engine, and determine the relative corrected speed n1r_air_2 of the low-pressure rotor required to ensure the stable operating performance of the engine under different total inlet pressures Pt2 of the engine in the in-flight idle state;

[0017] S23. Determine the minimum relative corrected speed n1r_air_3 of the low-pressure rotor at which the aircraft inlet can maintain stable operation during the deceleration process of the engine from the intermediate state to the idle state at different altitudes H and Mach numbers MA in the in-flight idle state;

[0018] S24. Calculate the minimum fuel flow rate Wf_air_min for stable combustion in the in-flight idle state;

[0019] S25. Select the higher value from the fuel supply required to maintain n1r_air_2, the fuel supply required to maintain n1r_air_3, and Wf_air_min as the main fuel control of the engine in the in-flight idle state.

[0020] According to at least one embodiment of the present application, in the above-mentioned slow-speed engine fuel control design method based on the requirements of engine-airframe matching, the main fuel control design method for the engine in the ground slow-speed state further includes:

[0021] S15. Conduct ground bench and altitude test bench tests to verify and correct the main fuel control of the engine in the ground slow-speed state.

[0022] According to at least one embodiment of the present application, in the above-mentioned slow-speed engine fuel control design method based on the requirements of engine-airframe matching, S11 is specifically:

[0023] Based on the ground slow-speed state thrust requirement given by the user, calculate the relative converted speed n1r of the low-pressure rotor of the engine in the ground slow-speed state, and correct it according to the results of the ground bench full-engine test. Take the total inlet pressure of the engine Pt2 = 101.325 kPa to obtain the relative converted speed n1r_grd_0 of the low-pressure rotor of the engine in the standard sea-level ground slow-speed state.

[0024] According to at least one embodiment of the present application, in the above-mentioned slow-speed engine fuel control design method based on the requirements of engine-airframe matching, S12 is specifically:

[0025] Select several envelope ground state points. Based on the relative converted speed n1r_grd_0 of the low-pressure rotor of the engine in the standard sea-level ground slow-speed state, calculate the overall parameters of the engine, and evaluate whether it meets the requirements of the engine's stable operating performance. If it cannot meet the requirements of the engine's stable operating performance, adjust the relative converted speed of the low-pressure rotor of the engine until it meets the requirements of the engine's stable operating performance, and obtain the relative converted speed n1r_grd_1 of the low-pressure rotor required to ensure the stable operating performance of the engine under different total inlet pressures Pt2 of the engine in the ground slow-speed state.

[0026] According to at least one embodiment of the present application, in the above-mentioned slow-speed engine fuel control design method based on the requirements of engine-airframe matching, the main fuel control design method for the engine in the in-flight slow-speed state further includes:

[0027] S26. Conduct ground bench and altitude test bench tests to verify and correct the main fuel control of the engine in the in-flight slow-speed state.

[0028] According to at least one embodiment of the present application, in the above-mentioned slow-speed engine fuel control design method based on the requirements of engine-airframe matching, S21 is specifically:

[0029] According to the engine operating envelope, calculate and determine the total pressure at the engine inlet. From small to large, select several typical altitude Mach number points on the same total pressure line at the engine inlet one by one. Calculate the minimum converted low-pressure engine speed that meets the aircraft cabin bleed air pressure requirement Pt27 under the condition of the same total pressure Pt2 at the engine inlet. Obtain the minimum converted low-pressure engine speed n1r_air_1 that meets the aircraft cabin bleed air pressure requirement Pt27 at different total pressures Pt2 at the engine inlet in the air.

[0030] According to at least one embodiment of the present application, in the above-mentioned idle state engine fuel control design method based on the engine-airframe matching requirement, S22 is specifically as follows:

[0031] Select several typical altitude Mach number points in the air. According to the minimum converted low-pressure engine speed n1r_air_1 that meets the aircraft cabin bleed air pressure requirement Pt27 at different total pressures Pt2 at the engine inlet, calculate the overall engine parameters and evaluate whether they meet the requirements of the engine stable operating performance. If they do not meet the requirements of the engine stable operating performance, adjust the relative converted low-pressure engine speed until the requirements of the engine stable operating performance are met, and obtain the relative converted low-pressure engine speed n1r_air_2 that ensures the engine stable operating performance under different total pressures Pt2 at the engine inlet in the air idle state.

[0032] According to at least one embodiment of the present application, in the above-mentioned idle state engine fuel control design method based on the engine-airframe matching requirement, S23 is specifically as follows:

[0033] Calculate and determine the air flow rate W1 at the engine inlet in the intermediate state at different altitudes H and Mach numbers MA in the entire envelope. Combine the aircraft inlet characteristics simulation to calculate the minimum air flow rate W1min at the engine inlet that the aircraft inlet can maintain stable operation during the deceleration process of the engine from the intermediate state to the idle state. Then, through simulation calculation, obtain the minimum relative converted low-pressure engine speed n1r_air_3 that the aircraft inlet can maintain stable operation during the deceleration process of the engine from the intermediate state to the idle state at different altitudes H and Mach numbers MA in the air idle state.

[0034] The present application has at least the following beneficial technical effects:

[0035] Provide an idle state engine main fuel control design method based on the engine-airframe matching requirement, distinguish the ground idle state and the air idle state, and conduct the main fuel control design separately. On the basis of meeting the idle thrust requirements at typical points and ensuring the normal operation of the engine, it can effectively meet the aircraft cabin bleed air pressure requirements under the full envelope operating conditions, the air flow matching between the aircraft inlet and the engine inlet, and the requirements of the engine stable operating performance, and is simple and easy to implement. Description of the Drawings

[0036] Figure 1 It is a schematic diagram of the main fuel control design method for the engine in the idle state based on the requirements of the engine-aircraft matching provided by the embodiments of the present application.

[0037] To better illustrate this embodiment, some components in the drawings are omitted, enlarged or reduced, which do not represent the dimensions of the actual product. In addition, the drawings are only for illustrative purposes and cannot be construed as a limitation to the present application. Detailed implementation manners

[0038] To make the technical solutions and their advantages of the present application clearer, the technical solutions of the present application will be further described clearly and completely below in conjunction with the drawings. It can be understood that the specific embodiments described herein are only partial embodiments of the present application, which are only used to explain the present application and are not intended to limit the present application. It should be noted that for the convenience of description, only the parts related to the present application are shown in the drawings, and other related parts can refer to the general design.

[0039] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present application should be the ordinary meanings understood by those of ordinary skill in the art to which the present application belongs. The terms indicating directions used in the description of the present application are only used to represent relative directions or positional relationships. When the absolute position of the object being described changes, its relative positional relationship may also change accordingly. The "including" used in the description of the present application means that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects.

[0040] In addition, it should be noted that unless otherwise clearly specified and limited, the terms such as "installation" and "connection" used in the description of the present application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. Those skilled in the art can understand their specific meanings in the present application according to the specific circumstances.

[0041] A main fuel control design method for the engine in the idle state based on the requirements of the engine-aircraft matching includes the main fuel control design method for the engine in the ground idle state and the main fuel control design method for the engine in the air idle state, as Figure 1 shown.

[0042] Main fuel control design method for the engine in the ground idle state:

[0043] S11. Determine the relative converted speed n1r_grd_0 of the low-pressure rotor of the engine in the ground idle state at standard sea level.

[0044] According to the thrust demand of the ground idle state given by the user, the relative corrected speed n1r of the low-pressure rotor of the engine in the ground idle state is calculated, and it is corrected according to the results of the ground test bench full-machine test. Taking the total pressure at the engine inlet Pt2 = 101.325 kPa, the relative corrected speed n1r_grd_0 of the low-pressure rotor of the engine in the standard sea-level ground idle state is obtained.

[0045] S12. Referring to the relative corrected speed n1r_grd_0 of the low-pressure rotor of the engine in the standard sea-level ground idle state, determine the relative corrected speed n1r_grd_1 of the low-pressure rotor required to ensure the stable operating performance of the engine under different total pressures Pt2 at the engine inlet in the ground idle state.

[0046] Select several envelope ground state points. According to the relative corrected speed n1r_grd_0 of the low-pressure rotor of the engine in the standard sea-level ground idle state, calculate the overall engine parameters and evaluate whether they meet the requirements of the engine's stable operating performance, specifically including the requirements for the engine's axial force, sealing of each cavity, overall vibration, combustion chamber combustion, etc. If the engine's stable operating performance requirements cannot be met, adjust the relative corrected speed of the engine's low-pressure rotor until the engine's stable operating performance requirements are met, and obtain the relative corrected speed n1r_grd_1 of the low-pressure rotor required to ensure the stable operating performance of the engine under different total pressures Pt2 at the engine inlet in the ground idle state. Specifically, the following table form can be designed: Pt2 XXX XXX XXX XXX XXX XXX n1r_grd_1 XXX XXX XXX XXX XXX XXX

[0047] For the envelope ground state points, the Mach number MA is 0, and the altitude H ranges from 0 to the upper limit of the ground state altitude.

[0048] S13. Calculate the minimum fuel flow rate Wf_grd_min for stable combustion in the ground idle state.

[0049] S14. Select the higher value from the fuel supply required to maintain n1r_grd_1 and Wf_grd_min as the main fuel control of the engine in the ground idle state.

[0050] S15. Use ground test bench and altitude test bench tests to verify and correct the main fuel control of the engine in the ground idle state.

[0051] Design method for the main fuel control of the engine in the in-flight idle state:

[0052] S21. Determine the minimum relative corrected speed n1r_air_1 of the engine's low-pressure conversion to meet the demand for the bleed air pressure Pt27 in the aircraft cockpit under different total pressures Pt2 at the engine inlet.

[0053] According to the engine operating envelope, calculate and determine the total pressure at the engine inlet. Generally, only when the total pressure at the engine inlet Pt2 < 101.325 kPa, select several typical altitude Mach number points on the same total pressure line at the engine inlet one by one from small to large. Calculate the minimum low-pressure converted engine speed that meets the aircraft cabin bleed air pressure Pt27 requirement under the condition of the same total pressure at the engine inlet Pt2. Obtain the minimum low-pressure converted engine speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement at different total pressures at the engine inlet Pt2 in the air. Specifically, the following table form can be designed:

[0054] S22. Refer to the minimum low-pressure converted engine speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement at different total pressures at the engine inlet Pt2, and determine the relative converted low-pressure rotor speed n1r_air_2 required to ensure the stable operation performance of the engine under the condition of different total pressures at the engine inlet Pt2 in the air at the idle state.

[0055] Select several typical altitude Mach number points. According to the minimum low-pressure converted engine speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement at different total pressures at the engine inlet Pt2, calculate the overall engine parameters and evaluate whether they meet the requirements for the stable operation performance of the engine. Specifically, it includes the requirements for the engine axial force, sealing of each cavity, overall engine vibration, combustion in the combustion chamber, etc. If the stable operation performance of the engine cannot be met, adjust the relative converted low-pressure rotor speed of the engine until the stable operation performance of the engine is met, and obtain the relative converted low-pressure rotor speed n1r_air_2 required to ensure the stable operation performance of the engine under the condition of different total pressures at the engine inlet Pt2 in the air at the idle state.

[0056] S23. Determine the minimum relative converted low-pressure rotor speed n1r_air_3 at which the aircraft inlet can maintain stable operation during the deceleration process of the engine from the intermediate state to the idle state at different altitudes H and Mach numbers MA in the air at the idle state.

[0057] Calculate and determine the air mass flow rate W1 at the engine inlet in the intermediate state under different altitudes H and Mach numbers MA in the full envelope. Generally, only when the Mach number Ma ≥ 1.0 is required. Combine the characteristics simulation of the aircraft inlet to calculate the minimum air mass flow rate W1min at the engine inlet that can maintain stable operation of the aircraft inlet during the deceleration process of the engine from the intermediate state to the idle state. According to the simulation calculation, obtain the minimum relative converted low-pressure rotor speed n1r_air_3 at which the aircraft inlet can maintain stable operation during the deceleration process of the engine from the intermediate state to the idle state at different altitudes H and Mach numbers MA in the air at the idle state. Specifically, the following table form can be designed:

[0058] S24. Calculate and obtain the minimum fuel flow rate Wf_air_min for stable combustion in the in-flight idle state.

[0059] S25. Select the highest value among the fuel supply amounts required to maintain n1r_air_2, the fuel supply amounts required to maintain n1r_air_3, and Wf_air_min as the main fuel control of the engine in the in-flight idle state.

[0060] S26. Verify and correct the main fuel control of the engine in the in-flight idle state through ground bench and altitude test stand tests.

[0061] The main fuel control design method of the engine in the idle state based on the requirements of the flight-propulsion matching disclosed in the above embodiments distinguishes between the ground idle state and the in-flight idle state, and conducts the main fuel control design respectively. On the basis of meeting the idle thrust requirements at typical points and ensuring the normal operation of the engine, it can effectively meet the aircraft cabin bleed air pressure requirements, the flow matching between the aircraft inlet and the engine inlet, and the engine stable operation performance requirements under the full envelope operating conditions, and is simple and easy to implement.

[0062] So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the drawings. Those skilled in the art should understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims

1. A design method for engine fuel control in slow-running state based on the demand for matching between aircraft and engine, characterized in that: Including the main fuel control design method of the engine in the ground idle state and the main fuel control design method of the engine in the air idle state; The design method of main fuel control of engine in ground idle state includes: S11, determining the relative conversion speed n1r_grd_0 of the low-pressure rotor of the engine at a standard sea level ground slow vehicle state; S12, referring to the relative conversion speed n1r_grd_0 of the low-pressure rotor of the engine at the standard sea level ground slow state, determine the relative conversion speed n1r_grd_1 of the low-pressure rotor required to ensure the stable working performance of the engine under different engine inlet total pressures Pt2 at the ground slow state; S13, calculating and obtaining the minimum fuel flow rate Wf_grd_min for maintaining stable combustion in the ground slow state; S14, select the higher one from the required fuel supply of n1r_grd_1 and Wf_grd_min as the main fuel control of the engine in the ground slow state; The design method of main fuel control of engine in air idle state includes: S21, determining the minimum engine low-pressure conversion speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement under different engine inlet total pressures Pt2; S22, referring to the minimum engine low-pressure conversion speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement under different engine inlet total pressures Pt2, determine the low-pressure rotor relative conversion speed n1r_air_2 required to ensure stable engine working performance under different engine inlet total pressures Pt2 in the air idle state; S23, determining the minimum low-pressure rotor relative conversion speed n1r_air_3 at which the aircraft inlet can maintain stable operation during the engine deceleration from the intermediate state to the slow state at different altitudes H and Mach numbers MA in the air slow state; S24, calculating and obtaining the minimum fuel flow rate Wf_air_min for maintaining stable combustion in an air idle state; S25, select a higher value from the fuel supply required to maintain n1r_air_2, the fuel supply required to maintain n1r_air_3, and Wf_air_min as the main fuel control of the engine in the air idle state.

2. The design method for engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: The design method of main fuel control of the engine in the ground idle state also includes: S15. Verify and correct the main fuel control of the engine at ground idle state by testing on ground test bench and high altitude test bench.

3. The design method of engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: S11 is as follows: According to the thrust requirement of the ground idle state given by the user, the relative conversion speed n1r of the low-pressure rotor of the engine at the ground idle state is calculated, and it is corrected according to the test results of the whole machine on the ground bench. The total pressure of the engine inlet Pt2 is taken as 101.325 kPa, and the relative conversion speed n1r_grd_0 of the low-pressure rotor of the engine at the standard sea level ground idle state is obtained.

4. The design method for engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: S12 is specifically: Select several envelope ground state points, calculate the overall engine parameters according to the relative converted speed n1r_grd_0 of the engine low-pressure rotor in the standard sea level ground slow state, and evaluate whether it meets the needs of the engine's stable working performance. If it cannot meet the needs of the engine's stable working performance, adjust the relative converted speed of the engine's low-pressure rotor until it meets the needs of the engine's stable working performance, and obtain the low-pressure rotor relative converted speed n1r_grd_1 required to ensure the engine's stable working performance under different engine inlet total pressures Pt2 in the ground slow state.

5. The design method of engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: The design method of main fuel control of the engine in the air idle state also includes: S26. Verify and correct the main fuel control of the engine in the air idle state by testing on the ground test bench and the high-altitude test bench.

6. The design method of engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: S21 is specifically: According to the engine operating envelope, the equal engine inlet total pressure line is calculated and determined. From small to large, several typical Mach number points at air altitudes are selected one by one on the same engine inlet total pressure line to calculate the minimum engine low-pressure converted speed that meets the aircraft cabin bleed air pressure Pt27 requirement under the same engine inlet total pressure Pt2. The minimum engine low-pressure converted speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement under different engine inlet total pressures Pt2 in the air is obtained.

7. The design method of engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: S22 is specifically: Select several Mach number points at typical altitudes in the air, calculate the overall engine parameters according to the minimum engine low-pressure converted speed n1r_air_1 that meets the aircraft cabin bleed air pressure Pt27 requirement under different engine inlet total pressures Pt2, and evaluate whether it meets the needs of stable engine working performance. If it cannot meet the needs of stable engine working performance, adjust the relative converted speed of the engine low-pressure rotor until it meets the needs of stable engine working performance, and obtain the low-pressure rotor relative converted speed n1r_air_2 required to ensure the stable working performance of the engine under different engine inlet total pressures Pt2 in the air idle state.

8. The design method of engine fuel control in idle state based on the aircraft-engine matching requirement according to claim 1 is characterized in that: S23 is specifically: The engine inlet air flow rate W1 in the intermediate state is calculated and determined at different heights H and Mach numbers MA of the full envelope. Combined with the aircraft inlet duct characteristics, the simulation calculation is used to obtain the minimum engine inlet air flow rate W1min at which the aircraft inlet can maintain stable operation during the engine deceleration from the intermediate state to the slow state. Then, the simulation calculation is used to obtain the minimum low-pressure rotor relative conversion speed n1r_air_3 at which the aircraft inlet can maintain stable operation during the engine deceleration from the intermediate state to the slow state at different heights H and Mach numbers MA in the air slow state.

Images