Mixture fraction field in a turbulent nonreacting propane jet

Time- and space-resolved mixture fraction measurements have been made throughout a turbulent nonreacting propane jet issuing into coflowing air using laser Rayleigh scattering, The objective of the measurements has been to obtain a better understanding of the Row structure and mixing process in turbulent variable-density jets where turbulent mixing has been decoupled from the effects of chemical heat release found in highly exothermic reacting jets. The measurements yield probability density distributions of the mixture fraction, from which the means, higher moments, and intermittency are calculated, Time histories of the Rayleigh signal are analyzed to obtain the power spectra and autocorrelations, Comparisons are made with results for other constant- and variable-density turbulent jets, and the observed differences are discussed.