
Accession Number : ADA186215
Title : Effects of Turbulence on Stationary and NonStationary Processes in CSystems.
Descriptive Note : Final technical rept. 1 Sep 8530 Nov 86,
Corporate Author : ILLINOIS UNIV AT URBANA DEPT OF AERONAUTICAL AND ASTRONAUTICAL ENGINEERING
Personal Author(s) : Roberts, Ted A ; Beddini, Robert A
PDF Url : ADA186215
Report Date : 01 Jun 1987
Pagination or Media Count : 36
Abstract : Turbularization of an acoustic boundary layer (Stokes Layer) on impermeable and permeable surfaces is analytically considered. The theoretical approach uses a secondorder closure model of turbulence. Both an approximate, closedform solution and a more comprehensive finite difference solution of the time dependent, parabolic, onedimensional governing equations are obtained. For simple acoustic boundarylayers on impermeable surfaces, both the approximate solution and the numerical results for the critical acoustic Mach number required for turbulent transition are qualitatively confirmed by experiment. Calculations for acoustic boundarylayers with transpiration (injection) indicate a substantial reduction of the acoustic Mach number required for transition, up to a limiting injection velocity that is frequency dependent. The results may provide a mechanism for flowrelated combustion instability in practical systems, particularly solid propellent rockets, since turbularization of the nearsurface combustion zone could result at relatively low acoustic Mach numbers. This report documents a completed phase of work which is concerned with the analysis of turbulent flow and heat transfer behavior in rocket chamber flows (Csystems). Keywords: Acoustic instability; Aeroacoustics; Solid propellent rocket engines; Transpiration; Turbulent boundary layer; Acoustic boundary layer; Combustion instability; Laminar boundary layer.
Descriptors : *COMBUSTION STABILITY, *TURBULENT BOUNDARY LAYER, ACOUSTICS, AERODYNAMICS, BOUNDARY LAYER, TIME DEPENDENCE, COMBUSTION CHAMBERS, CHAMBERS, COMBUSTION, EQUATIONS, FINITE DIFFERENCE THEORY, FLOW, HEAT TRANSFER, INJECTION, LAMINAR BOUNDARY LAYER, LAYERS, LIMITATIONS, MACH NUMBER, METHODOLOGY, NUMERICAL ANALYSIS, PERMEABILITY, ROCKETS, SOLID PROPELLANT ROCKET ENGINES, SOLUTIONS(GENERAL), STABILITY, SURFACES, THEORY, TRANSITIONS, TRANSPIRATION, TURBULENCE, TURBULENT FLOW, VELOCITY
Subject Categories : Combustion and Ignition
Fluid Mechanics
Acoustics
Distribution Statement : APPROVED FOR PUBLIC RELEASE