Accession Number : ADP004560

Title :   The Role of Convective Perturbations in Supercritical Inlet Oscillations,

Corporate Author : MCDONNELL DOUGLAS CORP ST LOUIS MO

Personal Author(s) : Bogar,T. J. ; Sajben,M.

Report Date : OCT 1984

Pagination or Media Count : 16

Abstract : Available experimental evidence on supercritical diffuser flow oscillations is reviewed, focusing on features that conflict with quasi-one-dimensional, linear acoustic theory. A model is proposed is which convective, transverse perturbations initiated by the shock and carried by the boundary layers are the dominant down-stream-moving disturbances in turn combine with upstream-moving acoustic waves to form the total oscillatory pattern. The boundary conditions at the two ends of the channel applicable to such flows are discussed. The reflection coefficients for pressure and velocity perturbations are related but not equal; some estimates of their values are given. The model offers a qualitative explantation for most non-acoustic features of the oscillations and suggests a possible mechanism for inlet/combustor coupling.

Descriptors :   *SUPERCRITICAL FLOW, *CONVECTION, *PERTURBATIONS, *SHOCK WAVES, DIFFUSERS, OSCILLATION, ONE DIMENSIONAL, ACOUSTIC WAVES, MODELS, BOUNDARY LAYER FLOW, INLETS, COMBUSTORS, VELOCITY, WAVE PROPAGATION, SYMPOSIA

Distribution Statement : APPROVED FOR PUBLIC RELEASE