Experimental and theoretical study of air flow with obstruction through test section of wind tunnel

Abstract EN

This paper estimates the sound and flow generated by a turbulent air flow in a duct from the knowledge of mean quantities (average velocity and sound pressure level).The sound excitation by fluid flow through duct can be used to predict fluid behavior.

This behavior can be carried out by discovering the relation between sound excitation and fluid flow parameters like Reynolds number, Strouhal number and frequencies of turbulent fluid flow.

However, the fluid flow container stability has to be taken in account simultaneously with fluid flow effect on sound generation and propagation.

The experimental system used in this work is air flow through subsonic wind tunnel duct.The sound pressure levels of air flows through test section of subsonic wind tunnel (at three air flow velocities2.5, 7.3 and 12.5 m/s) respectively were carried out experimentally.

The sound excitation or generation by air flow throughout the test section of subsonic wind tunnel without any obstruction can't be used to imagine the fluid behavior.

To predict fluid flow properties,an infinite cylinder was immersed in order to obstruct the air flow and generate a new source of sound.This case is relevant to a wide range of engineering applications including aircraft landing gear, rail pantographs and automotive side-mirrors.

Sound measurements have been taken in an anechoic room at Babylon University.

ANSYS program software is used to simulate all experimental results.The experimental and theoretical data that were presented in this paper will give further insight into the underlying sound generation mechanism.In the presented work, the linkage between sound generation and CFD results using thepresented work results and ANSYS simulation results was done.The results discuss the effects of fluid flow parameters such as Reynolds and Strouhal numbers on the sound generation, propagation features and vice-versa.

The results are compared with other researchers which give good agreements.