Bispectrum analysis transition identification method based on flight test pulsating pressure data

Abstract

A bispectrum analysis transition identification method based on flight test pulsating pressure data comprises the following steps: S1, filtering instantaneous pressure p measured by a pressure sensor on an aircraft through a moving average method, obtaining average pressure, and obtaining a distribution curve of pulsating pressure of the aircraft in a time domain; S2, dividing a distribution curve of pulsating pressure on a time domain, and intercepting pulsating pressure data in a plurality of delta t time periods, wherein the value range of the delta t is selected according to the sampling frequency; S3, performing bispectrum analysis on the pulsating pressure data in the delta t time period to obtain a pulsating pressure bispectrum value in each delta t time period; and S4, identifying the transition moment of the aircraft according to the pulsating pressure bispectrum values in different time periods. According to the method, the transition moment of the boundary layer of the aircraft in the flight test can be accurately identified, and data support is provided for follow-up trajectory optimization and thermal protection design of the aircraft.

Description

technical field [0001] The invention relates to a bispectral analysis transition identification method. Background technique [0002] Fluctuating pressure is an important physical quantity in aircraft design. High-speed aircraft are subject to strong pressure pulsations that can cause vibrations in cabin components and cause structural problems that affect the performance of the aircraft. According to the flight test results of our unit, the Reynolds number of the incoming flow increases as the flight height of the aircraft decreases, and the boundary layer on the surface of the aircraft transitions from laminar flow to turbulent flow. It is found that the amplitude of the pulsating pressure does not increase continuously. For the transition identification of flight test pulsating pressure data, there are few reports in the previous public literature. However, the moment of transition cannot be accurately judged simply by the amplitude of pressure pulsation. [0003] Most...

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Problems solved by technology

However, the moment of transition cannot be accurately judged simply by the amplitude of pressure pulsation

[0003] Most of the existing flight test transition measurement technologies use heat flow sensors and temperature sensors to judge the transition, but the frequency response of the heat flow and temperature sensors is low (generally tens of Hz to hundreds of Hz), which cannot take into account the measurement of disturbance waves in the boundary layer. (typically in kHz) characteristics

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