Accession Number:

AD0758254

Title:

A Study of Narrow Band Noise Generation by Flow Over Ventilated Walls in Transonic Wind Tunnels

Descriptive Note:

Corporate Author:

NIELSEN ENGINEERING AND RESEARCH INC MOUNTAIN VIEW CA

Report Date:

1973-02-01

Pagination or Media Count:

89.0

Abstract:

The report is concerned with the problem of environmental noise in transonic wind tunnels with ventilated, or perforated, walls. A brief critical review of past experimental investigations of such sounds is given. It is indicated that the instability of the separated shear layer over the cavities in a perforated wall should be the main agency for sound generation. A stability analysis of a nonparallel shear flow is undertaken. Relations such as the Strouhal numbers and minimum breadths, are given in terms of wind-tunnel aerodynamic parameters.

Subject Categories:

  • Test Facilities, Equipment and Methods
  • Acoustics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE