Accession Number : AD0759377

Title :   Fluctuating Pressure Characteristics in the Mixing Region of a Perturbed and Unperturbed Round Free Jet.

Descriptive Note : Technical memo.,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK ORDNANCE RESEARCH LAB

Personal Author(s) : Barefoot,Galen L.

Report Date : 04 AUG 1972

Pagination or Media Count : 103

Abstract : Theoretically, near-field pressure measurements in a turbulent flow can be used to predict far-field acoustic radiation. The basis of this study is the experimental verification of methods for obtaining the necessary data. Pressure intensity, spectra and cross-correlation data are obtained in three types of jet flows. The characteristic scale of pressure fluctuations is compared to the equivalent velocity scales. Consideration is given to errors associated with frequency response, low frequency cutoff and probe-turbulence interaction. Estimates of the various errors are given and certain correction procedures are suggested. (Author)

Descriptors :   (*JET MIXING FLOW, ACOUSTIC PROPERTIES), FLOW FIELDS, NOISE, SUBSONIC CHARACTERISTICS, MATHEMATICAL PREDICTION, WALLS, INTERFERENCE, TEST FACILITIES, FREQUENCY, RESPONSE, ERRORS

Subject Categories : Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE