Accession Number : AD0438477

Title :   WALL ROUGHNESS EFFECTS ON INVISCID NONEQUILIBRIUM FLOW IN DUCTS,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF

Personal Author(s) : Ortloff,C.

Report Date : 16 MAR 1964

Pagination or Media Count : 76

Abstract : The mean-square pressure fluctuation at the walls of a duct containing inviscid nonequilibrium flow is derived for cases of exponential and delta function autocovariance function wall roughnesses for subsonic and supersonic Mach numbers. Solutions for two- and three-dimensional sinusoidal walls are also included. For the limiting cases of frozen and equilibrium flows, the random roughness wall solutions for the firstorder potential are given in terms of source and sink-like singularities, the strengths of which are proportional to the local wall slope, and may be taken as randomly distributed along the wall. The mean-square fluctuation quantities are show to be related to the autocovariance function of the first derivative of the wall roughness function. The dependence on the meansquare pressure fluctuation of certain statistical properties of the roughened wall is show to be factorable from the pressure fluctuation expression; this leads to an easily determined estimate of the influence of certain properties of the roughness on the pressure fluctuation. Numerical examples are given to indicate the application of the method. (Author)

Descriptors :   (*DUCTS, GAS FLOW), NONEQUILIBRIUM FLOW, FRICTION, SURFACE PROPERTIES, VISCOSITY, EQUATIONS, FROZEN EQUILIBRIUM FLOW, PRESSURE, THREE DIMENSIONAL FLOW, SUBSONIC FLOW, SUPERSONIC FLOW

Distribution Statement : APPROVED FOR PUBLIC RELEASE