Accession Number : AD0683370

Title :   AN INVESTIGATION OF SOUND-FIELD STRUCTURES IN CLOSED CABINS AND COMPARTMENTS BY MEANS OF CORRELATION METHODS,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Dmitrieva,L. V. ; Pisarevskii,N. N.

Report Date : 03 JUL 1968

Pagination or Media Count : 9

Abstract : The main characteristics of acoustic fields in closed rooms and compartments are determined from a space-time correlation function by measuring acoustic pressures at two points. The character of the correlation function between acoustic pressures and the spacing between the two points makes it possible to evaluate irregularities in the acoustic-energy flux. The correlation functions are found by two methods, called the 'radial' and 'angular' correlation method; in some cases, radial and angular correlation functions are insufficient for characteristizing the acoustic-field structure. Isocorrelation curves for several sections are then plotted. This is demonstrated with an example of an aircraft fuselage. The sound field was established by means of a loud speaker placed in the fuselage. Measurements were made in the octave region of white noise at an average frequency of 800 Hz, and the correlation coefficients were registered when one microphone was located in the cabin's center and another was moved automatically. The measured isocorrelation curves are shown. (Author)

Descriptors :   (*STRUCTURES, *ACOUSTIC PROPERTIES), CORRELATION TECHNIQUES, AIRCRAFT CABINS, USSR

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE