Accession Number : ADA190101

Title :   Basic Instability Mechanisms in Chemically Reacting Subsonic and Supersonic Flows.

Descriptive Note : Annual technical rept. 30 Sep 86-29 Sep 87,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Toong, Tau-Yi

PDF Url : ADA190101

Report Date : 23 Oct 1987

Pagination or Media Count : 30

Abstract : The nature of turbulence-combustion interactions was examined by the use of simultaneous dual-thermocouple velocity and LDV-thermocouple measurements, which showed that the presence of the high-frequency velocity (in a direction normal to the flame brush) and temperature fluctuations within slowly drifting turbulent premixed V-flames was associated with changes in the flame shapes, thicknesses, and propagation speeds. Unlike the RMS normal-velocity fluctuations which assumed maximum values within the reaction zone, the RMS tangential-velocity fluctuations remained almost constant, implying that the flame-generated turbulence was in the normal direction. Furthermore, cross-correlation coefficients of simultaneous velocity and temperature fluctuations remained positive within the flame, with values involving normal velocities higher than those involving tangential components. Keywords: Turbulence, Combustion interactions, Instability mechanisms, Dist turbulent flames.

Descriptors :   *COMBUSTION, *TURBULENCE, *COMBUSTION STABILITY, *FLAME PROPAGATION, COEFFICIENTS, CROSS CORRELATION, FLAMES, HIGH FREQUENCY, INTERACTIONS, SHAPE, STABILITY, SUBSONIC FLOW, SUPERSONIC FLOW, SYNCHRONISM, TANGENTS, TEMPERATURE, THICKNESS, VARIATIONS, VELOCITY, OPTICAL DETECTORS, LASER VELOCIMETERS, DOPPLER EFFECT

Subject Categories : Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE