A Measuring Method of Derivative of Aircraft Longitudinal Moment to Pitch Angular Velocity

Abstract

The invention discloses a method for measuring a derivative of aircraft longitudinal moment on pitching angular velocity. The method comprises the following steps: firstly constructing a testing wind tunnel, wherein the testing wind tunnel comprises a wind tunnel inlet, a wind tunnel pipeline and a rectifying blade; then horizontally and fixedly arranging an aircraft model in the wind tunnel pipeline through a supporting frame and arranging a data measuring instrument at the connection portion of the aircraft model and the supporting fame; secondly, rotating the testing wind tunnel at a constant speed at the angular velocity q1, measuring the longitudinal moment (img file='DDA0000593412430000011.TIF' wi='96' he='53' / ) of the aircraft model at the moment; successively, rotating the testing wind tunnel at a constant speed at the angular velocity q2 and measuring the longitudinal moment (img file='DDA0000593412430000012.TIF' wi='93' he='52' / ) of the aircraft model at the moment; finally, calculating the derivative of the aircraft longitudinal moment on the pitching angular velocity according to the q1 and the q2 as well as (img file='DDA0000593412430000013.TIF' wi='204' he='55' / ). The method has the benefit that the derivative of aircraft dynamic torque on pitching angular velocity can be directly measured through the wind tunnel test, so that the test period, the test expense and the test complexity are effectively reduced.

Description

technical field [0001] The invention relates to the technical field of flight control, in particular to a method for measuring the derivative of an aircraft longitudinal moment to pitch angular velocity. Background technique [0002] The derivative of the vertical moment of the aircraft to the pitch angular velocity measured by the traditional aircraft dynamic derivative measurement test is indirectly measured and calculated, which is determined by the formula of the longitudinal moment of the aircraft. [0003] The aircraft longitudinal moment formula is as follows: [0004] [0005] In the formula, M a Indicates the moment of the aircraft in flight state, ΔM a Indicates the size of the variable of moment when the aircraft is in zero-lift state, Indicates the derivative of the aircraft torque to the flight speed, ΔV indicates the variation of the speed, Indicates the derivative of the aircraft torque to the angle of attack, Δα indicates the variation of the angle o...

AI Technical Summary

Problems solved by technology

[0007] Using the method of forced motion to apply sinusoidal motion to the aircraft can obtain the rate of change of the angle of attack respectively and pitch angular velocity q on the longitudinal moment of the aircraft, but the influence of the reduction frequency of the applied motion needs to be considered. Different reduction frequencies have a greater impact on the test value, and it is necessary to continuously use different reduction frequency values ​​for testing, which increases Test cost and test cycle

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