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):

Report Date:

1987-10-23

Pagination or Media Count:

30.0

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.

Subject Categories:

  • Combustion and Ignition

Distribution Statement:

APPROVED FOR PUBLIC RELEASE