Accession Number:

AD0611126

Title:

ENTROPY BOUNDARY LAYERS,

Descriptive Note:

Corporate Author:

AVCO EVERETT RESEARCH LAB EVERETT MASS

Personal Author(s):

Report Date:

1965-01-01

Pagination or Media Count:

16.0

Abstract:

Croccos equation for the entropy gradients in an inviscid compressible flow is extended to flows with viscosity and conductivity using the boundary layer equations of motion. The general structure of the entropy boundary layer is discussed and entropy profiles are presented for the Pr 1 boundary layer using cold, hot and adiabatic wall conditions at several representative subsonic and supersonic Mach numbers. For an adiabatic wall the entropy profile has an inverse boundary layer structure in velocity coordinates, the greatest variation occurring near the outer edge of the boundary layer, while the entropy near the wall is essentially constant. For cold wall conditions total enthalpy gradients and vorticity have opposing effects, and the entropy profile can have a maximum provided M at infinity exceeds a minimum critical value. Entropy is a convenient state variable with which to express the variation of vorticity and total enthalpy in a supersonic boundary layer prior to a rapid expansion or separation and can be used to describe these two phenomena in much the same manner that entropy is presently used to describe the flow behind a curved shock wave. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE