Accession Number : AD0862256

Title :   On Surface Gravity Waves in Heterogeneous Shear Flows.

Descriptive Note : Technical rept.,

Corporate Author : FLORIDA STATE UNIV TALLAHASSEE

Personal Author(s) : Lau, Joseph P.

Report Date : 1969

Pagination or Media Count : 21

Abstract : Two-dimensional surface waves in a stable stratified, inviscid and incompressible fluid, in which the mean flow varies only with depth, are studied. The vertical characteristic wavelength of these waves is assumed small compared to the characteristic scale-length of the fluid so that a geometric optics approximation yields a systematic expansion. Asymptotic results are obtained by the related W.K.B.J. method. In the absence of a critical level, at which the horizontal phase velocity relative to the mean flow vanishes, only discrete surface gravity wave mades exist. Each mode is reflected internally at a turning level as if a horizontal bottom exists. In contrast, continuous spectra of surface wave modes associated with the existence of critical levels are not affected by horizontal boundaries below their respective critical levels. (Author)

Descriptors :   (*TWO DIMENSIONAL FLOW, STABILITY), GRAVITY, SURFACE PROPERTIES, VISCOSITY, STABILITY, EQUATIONS OF MOTION, SHEAR STRESSES, INCOMPRESSIBLE FLOW.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE