Accession Number:

ADA001932

Title:

Wave Mechanics of Boundary Layer Turbulence and Noise,

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING

Personal Author(s):

Report Date:

1974-01-01

Pagination or Media Count:

29.0

Abstract:

Recent advances in the understanding of the structure of boundary layer turbulence form the basis of a new conceptual model for the fluctuating velocity field. In this, an active mode of small-scale motion is coupled to a large-scale passive mode by aid of wave mechanical considerations. The small-scale motion originates during the intermittent bursting in the wall layer leading to excitation of large-scale, damped, traveling shear waves. It is argued that the passive wave-like mode gives the major contribution to the pseudosound, whereas the active bursting mode serves as the predominant source for the radiative noise. It is shown that the bursting mode gives rise to compact noise sources of both dipole and quadrupole type whose strengths are related to the turbulent shear stress production.

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE