Проблемы обнаружения отрыва потока датчиками давления на беспилотных летательных аппаратах с пропеллером

An experimental study of pulsations characteristics of the zone of flow separation arising at a small airplane-type UAV with a pushing two-blade propeller were carried out. The measurements were done in wind tunnel by unsteady pressure sensors and microphones built into the skin of the UAV for the test cases with and without a rotating propeller. A significant effect of the propeller on the level of pulsations was found. An increase of the incoming flow velocity led to a weakening of this effect. Analysis of the spectral data of the disturbances did not reveal a direct relationship between the propeller noise and the unsteady characteristics of the separation zone.

On the Application of Wavelet Transform in Jet Aeroacoustics

Wavelet transform has become a common tool for processing non-stationary signals in many different fields. The present paper reports a review of some applications of wavelet in aeroacoustics with a special emphasis on the analysis of experimental data taken in compressible jets. The focus is on three classes of wavelet-based signal processing procedures: (i) conditional statistics; (ii) acoustic and hydrodynamic pressure separation; (iii) stochastic modeling. The three approaches are applied to an experimental database consisting of pressure time series measured in the near field of a turbulent jet. Future developments and possible generalization to other applications, e.g., airframe or propeller noise, are also discussed.

NUMERICAL SIMULATION OF THE LIGHT AIRCRAFT PROPELLER NOISE UNDER STATIC CONDITION

The problem of simulation the noise generated during the operation of the propeller is considered. Calculation methods are described and numerical simulation of the noise of a light aircraft propeller by the acoustic-vortex method is performed. The results of numerical modeling of the tonal components of the propeller noise when operating under static conditions are compared with experimental data and calculation results based on a semiempirical model.