A method for stability control of aero-engines under inlet distortion conditions

Abstract

This invention discloses a method for stability control of aero-engines under inlet distortion conditions. First, a dynamic process calculation and simulation model of the engine is established. A minimum stability margin control value is set according to the requirements of aero-engine operation safety. Then, the comprehensive distortion index and engine distortion sensitivity coefficient are determined according to the inlet distortion of the aero-engine, and the stability margin loss of the aero-engine is calculated. Next, the remaining stability margin of the engine is calculated in real time according to the operating parameters of the aero-engine and compared with the set minimum stability margin control value. If the remaining stability margin is less than the minimum stability margin control value, the preset control parameters are adjusted to perform stability control, so that the remaining stability margin of the engine is increased to above the minimum stability margin control value, thereby ensuring the stable and safe operation of the aero-engine.

Description

Technical Field

[0001] This invention relates to the field of aero-engine control systems, and more particularly to a method for stability control of aero-engines under inlet distortion conditions. Background Technology

[0002] In the design and operation of aircraft engines, aerodynamic stability is an important technical safety issue. With the deepening of research and the continuous development of technology, the design requirements of aero engines are gradually moving towards high pressure ratio, high thrust-to-weight ratio and low fuel consumption rate. At the same time, this also puts forward higher requirements for the aerodynamic stability of aero engines.

[0003] During the aerodynamic processes inside an engine, the intense pressurization of the airflow within the compressor / fan causes aerodynamic instability. When an aircraft engine operates under different flight conditions, factors such as engine inlet distortion reduce the engine's stability margin, leading to unstable operation. When an engine becomes unstable and enters a rotating stall or surge state, it severely impacts engine performance, specifically manifesting as decreased engine thrust and increased fuel consumption; increased compressor rotor blade vibration, causing structural damage to the engine; and a reduced stable operating range in the combustion chamber, increasing the likelihood of engine shutdown.

[0004] Therefore, there is a need for a technical method to control the engine stability margin to ensure a certain level of safe engine operation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for controlling the stability of an aero-engine under intake distortion conditions, addressing the deficiencies mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for stability control of an aero-engine under inlet distortion conditions includes the following steps:

[0008] Step 1), establish a simulation model for the engine's dynamic processes;

[0009] Step 2), set the minimum stability margin control value according to the requirements of aircraft engine operation safety;

[0010] Step 3) Calculate the engine's residual stability margin based on the engine dynamic process simulation model:

[0011] Step 3.1) Determine the engine's overall distortion index based on the engine inlet distortion.

[0012] Step 3.2) Determine the engine distortion sensitivity coefficient based on the engine speed changes during operation;

[0013] Step 3.3) Calculate the stability margin loss of the aero-engine based on the engine's comprehensive distortion index and distortion sensitivity coefficient, and then calculate the engine's remaining stability margin.

[0014] Step 4) Compare the engine's remaining stability margin with the minimum stability margin control value;

[0015] Step 4.1) If the remaining stability margin is greater than the minimum stability margin control value, it means that the working state is stable and there is no need to control the stability margin. Directly enter the main control.

[0016] Step 4.2): If the remaining stability margin is less than the minimum stability margin control value, then stability control is performed.

[0017] The preset change in control parameters is calculated based on the difference between the remaining stability margin and the minimum stability margin control value. The engine operating state is then adjusted according to the preset change in control parameters to increase the engine's remaining stability margin above the minimum stability margin control value.

[0018] As a further optimization of the aero-engine stability control method under intake distortion conditions of the present invention, the preset control parameters in step 4.2) include fuel flow rate and nozzle area.

[0019] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0020] 1. The engine stability margin is controlled throughout the entire operation process, the remaining stability margin increases, and the safety and stability of engine operation increases;

[0021] 2. It can increase the stability margin of the engine during acceleration, and the loss of engine performance can be controlled within a certain range;

[0022] 3. Controlling the engine before it enters an unstable operating state ensures stable and safe engine operation, reduces the impact of unstable operating states on the engine, and makes the engine work more stably and has a longer service life. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the stability control method for aero-engines according to the present invention. Implementation

[0024] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0025] This invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully express the scope of the invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0026] like Figure 1 As shown, this invention discloses a method for stability control of an aero-engine under inlet distortion conditions, comprising the following steps:

[0027] Step 1), establish a simulation model for the engine's dynamic processes;

[0028] Based on existing aero-engine component characteristic data, and considering the engine's main control laws, component limiting parameters, and engine component volume effects, a dynamic process calculation and simulation model for the engine is established. This model can calculate the engine's transient dynamic characteristics and analyze the changes in engine dynamic process parameters.

[0029] Step 2), set the minimum stability margin control value according to the requirements of aircraft engine operation safety;

[0030] Step 3) Calculate the engine's residual stability margin based on the engine dynamic process simulation model:

[0031] Step 3.1) Determine the engine's overall distortion index based on the engine inlet distortion.

[0032] Step 3.2) Determine the engine distortion sensitivity coefficient based on the engine speed changes during operation;

[0033] Step 3.3) Calculate the stability margin loss of the aero-engine based on the engine's comprehensive distortion index and distortion sensitivity coefficient, and then calculate the engine's remaining stability margin.

[0034] Step 4) Compare the engine's remaining stability margin with the minimum stability margin control value;

[0035] Step 4.1) If the remaining stability margin is greater than the minimum stability margin control value, it means that the working state is stable and there is no need to control the stability margin. Directly enter the main control.

[0036] Step 4.2): If the remaining stability margin is less than the minimum stability margin control value, then stability control is performed.

[0037] The preset change in control parameters is calculated based on the difference between the remaining stability margin and the minimum stability margin control value. The engine operating state is then adjusted according to the preset change in control parameters to increase the engine's remaining stability margin above the minimum stability margin control value.

[0038] As a further optimization of the aero-engine stability control method under intake distortion conditions of the present invention, the preset control parameters in step 4.2) include fuel flow rate and nozzle area.

[0039] Understandably, depending on engine design and operational requirements, other control variables can be selected, including fan guide vane angle, compressor guide vane angle, valve area, etc. In application, one control variable can be used for control, or multiple control variables can be controlled simultaneously; that is, selecting the appropriate control variable is sufficient to achieve the desired result.

[0040] The following examples further illustrate this application; it is understood that these examples do not constitute any limitation on this application.

[0041] In this example, the minimum stability margin control value is set to SMMIN=6.6, the engine inlet comprehensive distortion index is set to 5%, and the engine distortion sensitivity coefficient is set to α=0.85.

[0042] The engine's operating stability margin loss DSM is calculated using the formula DSM=W*α*100, and then the engine's remaining stability margin SM is calculated.

[0043] The engine dynamic process calculation simulation model starts from the engine's initial state and establishes the dynamic process of the engine starting from ground operation. During engine operation, the stability margin also changes dynamically over time. When the stability margin falls below the minimum stability margin control value at a certain moment, stability control is implemented.

[0044] Fuel flow rate is selected as the stability control variable. Based on the interpolation between the remaining stability margin and the minimum stability margin control value at the current moment, the change in fuel flow rate is generated according to the control law. This change is then combined with the main control program to change the engine operating point so that the engine's remaining stability margin is greater than the minimum stability margin control value.

[0045] Therefore, under certain conditions of import distortion index and engine distortion sensitivity coefficient, the present invention sets the minimum stability margin control value when the engine is working according to the engine's working needs. When the remaining stability margin when the engine is working is lower than the minimum control value, the engine stability control selects appropriate control parameters in the active control to adjust the engine's operating point to the lower left, thereby increasing the remaining stability margin and enabling the engine to work stably.

[0046] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0047] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the stability of an aero-engine under inlet distortion conditions, characterized in that, Includes the following steps: Step 1), establish a simulation model for the engine's dynamic processes; Step 2), set the minimum stability margin control value according to the requirements of aircraft engine operation safety; Step 3) Calculate the engine's residual stability margin based on the engine dynamic process simulation model: Step 3.1) Determine the engine's overall distortion index based on the engine inlet distortion. Step 3.2) Determine the engine distortion sensitivity coefficient based on the engine speed changes during operation; Step 3.3) Calculate the stability margin loss of the aero-engine based on the engine's comprehensive distortion index and distortion sensitivity coefficient, and then calculate the engine's remaining stability margin. Step 4) Compare the engine's remaining stability margin with the minimum stability margin control value; Step 4.1) If the remaining stability margin is greater than the minimum stability margin control value, it means that the working state is stable and there is no need to control the stability margin. Directly enter the main control. Step 4.2): If the remaining stability margin is less than the minimum stability margin control value, then stability control is performed. The preset change in control parameters is calculated based on the difference between the remaining stability margin and the minimum stability margin control value. The engine operating state is then adjusted according to the preset change in control parameters to increase the engine's remaining stability margin above the minimum stability margin control value.

2. The method for controlling the stability of an aero-engine under inlet distortion conditions according to claim 1, characterized in that, The preset control parameters in step 4.2) include the fuel flow rate and the nozzle area.

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