Aerial turbofan engine control method based on surge margin estimation model

Abstract

The invention discloses an aerial turbofan engine control method based on a surge margin estimation model. The modeling of the provided surge margin estimation model is divided into two parts, namely an undistorted model during conventional flight and a loss model during super-maneuver flight, wherein the undistorted model is realized by screening the optimal model input and modeling through a nonlinear fitting method based on a surge margin feature selection algorithm; the loss model is realized by estimating the aircraft engine inlet distortion degree based on an online attack angle prediction model and calculating to obtain the surge margin loss during distortion. The stability of an engine is predicted in real time by utilizing the estimation model, a turbine fall ratio control instruction is subjected to margin loss compensation on the basis that a conventional control loop of the engine is not changed, and high-stability control is realized. The aircraft engine can be guaranteed to work stably and efficiently, and the surge margin of the aircraft engine is controlled to be 11-13 percent.

Description

technical field [0001] The invention relates to an aviation turbofan engine control method, in particular to an aviation turbofan engine control method based on a surge margin estimation model, and belongs to the technical field of aerospace control. Background technique [0002] Supermaneuverability is one of the necessary technologies for modern fighter jets. However, in the post-stall state, the aeroengine needs to work under the condition of large angle of attack and side slip angle. In severe cases, it may even produce unstable working phenomena such as surge. In response to this problem, in 1993, NASA carried out research on aero-engine high stability control (HISTEC, High Stability Engine Control), which mainly used the pressure ratio loss of compression parts to approximate the surge margin loss, and then through the design of advanced control Regularly correct the transient working lines of fans and compressors in time to ensure sufficient stability margins for aer...

AI Technical Summary

Problems solved by technology

Establishing aero-engine surge margin estimation model has always been a difficult problem in anti-surge / elimination control. Chen Tinghao et al. divided the surge margin into two parts: the loss of surge margin during distortion and the undistorted value during conventional flight. Calculated separately, but it adopts the idea of ​​equal conversion air flow to obtain the surge margin (actually, the equal conversion speed line should be taken), and directly calculates through the pressure ratio of the compression parts, that is, the surge margin can be regarded as measurable. This method There are certain limitations at low speeds

Furthermore, traditional nonlinear fitting methods use flight altitude, Mach number, main fuel volume, nozzle area, etc. as model inputs based on experience, but these parameters are not closely related to surge margin, so it is difficult to realize Accurate Identification of Surge Margin

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