Accession Number : ADA133977

Title :   Mechanisms of Exciting Pressure Oscillations in Ramjet Engines.

Descriptive Note : Interim rept. 20 Aug 80-19 Aug 81,


Personal Author(s) : Culick,F E C ; Marble,F E ; Zukoski,E E

PDF Url : ADA133977

Report Date : 01 Oct 1982

Pagination or Media Count : 10

Abstract : This report covers the first year of an experimental and analytical program concerned with problems of pressure oscillations in ramjet engines. Initial tests have been performed showing that the blowdown facility operates as planned; modifications for operation at higher pressure have been started. An analysis of the response of a normal shock wave to pressure oscillations has been completed and will be used as the upstream boundary condition in calculations of the acoustical field. Construction of a general framework for analyzing the instabilities in engines has been started, including modeling of the steady flow field. Special attention is being directed to unsteady shear layers and combustion in a vortex as a mechanism for exciting pressure oscillations. Utilizing the physical model derived from the transient burning of a flame in a vortex field, it has been possible to correlate screech data for a wide variety of fuels. (Author)

Descriptors :   *Ramjet engines, Oscillation, Pressure, Combustion stability, Shock waves, Flow fields, Steady flow

Subject Categories : Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE