Method for pre-estimating flight path of wind tunnel free flight test model

Abstract

The invention provides a method for pre-estimating flight path of a wind tunnel free flight test model, and the method comprises the steps: 1, obtaining an attack angle - mechanics coefficient table of a flight model; 2, setting the initial attack angle value theta0 of a free flight test, a transmission position, and an initial transmission speed, obtaining the mechanics coefficient at the initial attack angle value theta0 through linear interpolation, and enabling the initial attack angle value theta0 and the corresponding mechanics coefficient to serve as an initial transmission parameter D0; 3, calculating and obtaining pre-estimated flight path data through a Runge-Kutta method after flight at the transmission position; 4, repeatedly carrying out the steps 2 and 3 when the pre-estimated flight path data does not meet the testing requirements, obtaining a new pre-estimated flight path, and carrying out step 4 till the new pre-estimated flight path meets the testing requirements. The method pre-estimates the flight path of free flight of a model in a wind tunnel, enables the flight path to stay for longer tie in an observation region, and obtains more effective information during testing.

Description

technical field [0001] The invention belongs to the field of wind tunnel flight test, in particular to a method for estimating the flight trajectory of a wind tunnel free flight test model. Background technique [0002] Wind tunnel free flight test is an important method in the study of the dynamic characteristics of aircraft. The test principle is to truly reproduce the dynamic characteristics of the aircraft under the action of unsteady aerodynamic forces in the free flight state, and to directly record the motion characteristics of the aircraft through high-speed photography while ensuring that the dynamics of the wind tunnel test and the flight state are similar. At the same time, based on the aerodynamic parameter identification technology, according to the model angular displacement and linear displacement data recorded by the high-speed camera in the test, the static and dynamic stability derivative coefficients of the aircraft, as well as the drag and lift coefficien...

AI Technical Summary

Problems solved by technology

However, if the launch speed and launch position are repeatedly adjusted through the actual wind tunnel free flight test results again and again, it will also cause a large waste of wind tunnel blowing times and test models. Therefore, if certain launch parameters and launch positions can be adjusted before the test Under normal circumstances, the model flight trajectory passing through the observation window area is estimated, and then by adjusting the launch parameters and launch position, it is estimated that the model flight trajectory passing through the observation window area can meet the launch parameters and launch position required by the test. It is of great significance to ensure the test effect and greatly reduce the cost of the wind tunnel free flight test

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