METHOD OF SIMULATING IN WIND TUNNELS EFFECT OF VERTICAL GUST OF WIND ON NEAR FIELD OF AIRCRAFT AND ON LOUDNESS OF SOUND SHOCK ON GROUND Russian patent published in 2024 - IPC G01M9/00 

FIELD: measuring.

SUBSTANCE: invention relates to aerodynamics and is intended for investigation of near pressure field of model at supersonic flow in wind tunnel. Method includes application of barosensitive coating on section of measuring wall of working part of wind tunnel, length, width and location along the length of the working part of which are such that perturbations emanating from the lower surface of the aircraft model fall on the section with the applied pressure-sensitive coating. Tests are carried out with simulation of the initial moment of the effect of a stepped vertical gust of wind on the near field of the model, which is held in a certain area of the working part by a knife holder. Simulation of the effect of a stepped vertical wind gust at the flight altitude on the near pressure field is carried out by changing the angle of attack of the model, which is achieved by establishing between the model and the lower part of the blade holder of the part which changes the angle of attack of the model. Pressure in the near field of the model is measured by means of a barosensitive coating, successively changing the angle of attack, which corresponds to the range of interest of changes in the vertical wind gust. From simulation of dynamics of aircraft movement under action of vertical gust of wind with speed, dependence of change in time of angle of attack is found, and, accordingly, with equality of angle of attack in experiment, angle of attack during simulation of dynamics of aircraft movement, dependence of pressure in near field on time is found. Using the time dependence of the pressure in the near field of the model, the dependence of the sound impact volume on the ground on time is found in various metrics at a given law of variation of the vertical wind gust speed over time.

EFFECT: high accuracy of predicting the occurrence of exceeding the permissible loudness of a sound impact in a supersonic flight of a supersonic civil aircraft.

1 cl, 4 dwg