Accession Number:

ADA242027

Title:

Local Extinction Mechanisms in Non-Premixed Turbulent Combustion

Descriptive Note:

Final rept. 1 May 1988-30 Jun 1990

Corporate Author:

GENERAL ELECTRIC CORPORATE RESEARCH AND DEVELOPMENT SCHENECTADY NY

Personal Author(s):

Report Date:

1991-08-31

Pagination or Media Count:

78.0

Abstract:

The goal of this research was a quantitative understanding of turbulence-chemistry interactions pertinent to future aeropropulsion combustors. For example, 1 flameout and relight in turbine combustors are related to interactions of turbulence with chain-branching reactions 2 hydrogen burnout in supersonic combustors is related to interactions with recombination reactions and 3 emissions of NOx, CO, smoke and other observables are related to nonequilibrium in the populations of intermediate species such as oxyhydrogen radicals and CxHCy. A bluff-body stabilized turbulent diffusion flame, time- and space-resolved lase Raman measurements of major species, and a nonequilibrium computational fluid mechanics code were applied to the problem. Principal conclusions include 1 Turbulent jet flames are being abandoned in the search for more intensely turbulent flames. 2 An axisymmetric bluff-body stabilized turbulent diffusion flame burner is a reasonable choice for combustion research at high Reynolds numbers, approaching blowoff. 3 Raman scattering for measurements of major species and temperature can be extended into the sootingchemiluminescent environment of methane flames. Space- and time-resolved Raman scattering measurements were made in bluff-body stabilized COH2N2 and CH4 flames at conditions approaching blowoff. 4 A thermochemical submodel based on partial equilibrium in the oxyhydrogen radical pool was developed for the 27.5 CO32.3 H240.2 N2-air system. The chemistry can be described in terms of two scalars. The elliptic form of the time-averaged Navier Stokes equations with k-epsilon closure was solved using an iterative finite- volumepressure-correction algorithm.

Subject Categories:

  • Combustion and Ignition
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE