Aerodynamic stability predicting and estimating method of aerial engine under counter thrust state

Abstract

Disclosed is an aerodynamic stability predicting and estimating method of an aerial engine under a counter thrust state. The method comprises the following steps of, firstly, performing aeroplane / engine integrated counter thrust air turbulence field fully-three-dimensional numerical simulation under the counter thrust state and obtaining the distortion maps and the distortion indexes of the inlet flow field of the engine under the counter thrust state; under the premise of obtaining the distortion indexes of the inlet flow field of the engine under different skating speeds of the aeroplane in the counter thrust state, performing integral stability computing analysis on influence of inlet flow field distortion on the aerodynamic stability of the engine in the counter thrust state; thirdly, taking the engine inlet flow field distortion maps obtained through three-dimensional flow field computing as the target to design an inlet flow field distortion generator used for aerial engine bench tests; fourthly, performing engine bench tests through the engine inlet flow field distortion generator, during the tests, starting a counter thrust device to measure the working state of the engine in real time and further to estimate the engine aerodynamic stability in the counter thrust state when inlet flow field distortion exists.

Description

Technical field: [0001] The invention relates to a method for predicting and evaluating the aerodynamic stability of an aeroengine under a reverse thrust state, and belongs to the technical field of aeroengines. Background technique: [0002] As the "heart" of an aircraft, ensuring its stable operation under different flight conditions is a necessary guarantee for achieving high safety and reliability of the aircraft. When obtaining an aeroengine airworthiness certificate, the aerodynamic stability of the engine is an assessment that must be completed. [0003] The thrust reverser is recognized by the aviation industry as a permanent part of the exhaust system of a turbofan engine with a large bypass ratio, which can significantly shorten the landing run distance of large aircraft (especially on wet and icy runways), and can be used It is used for rapid go-around when emergency stop taxi takeoff and landing are unsuccessful, among them, in terms of military aircraft, it can...

AI Technical Summary

Problems solved by technology

Such an evaluation period seems to be relatively late. Once a problem is found in the evaluation test, it will be necessary to make major changes to the engine or thrust reverser, or even push it to a new start. This will inevitably seriously affect the development progress of the engine and even the aircraft.

[0008] (2) The evaluation test costs are high, the cycle is long, and the safety is low

If during the test, the stability of the engine fails to meet the requirements and the engine becomes unstable, this will inevitably pose a serious threat to the safety of the flight test.

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