Turbulence-Radiation Interactions in Nonreactive Flow of Combustion Gases

Abstract

A nonreactive hot mixture of radiatively participating species, typically carbon dioxide and water vapor, may be found in the exhaust sections of almost all combustors. Since the scalar fluctuations in such nonreactive flows are substantially smaller than in flames, it is commonly believed that the effects of turbulence-radiation interactions (TRI) on altering wall heat fluxes in nonreactive flows are negligible. Such belief, however, has not been substantiated by evidence to date. The purpose of this note is to investigate the conditions under which turbulence-radiation interactions may be important in nonreactive flows. The final outcome was found to be largely dependent on how the scalar fluctuations correlate, rather than the magnitude of the fluctuations themselves. It was found that for most situations of practical interest, TRI effects are indeed negligible.