Mixing structure of plane self-preserving buoyant turbulent plumes

Measurements of the structure of plane buoyant turbulent plumes are describ ed emphasizing conditions in the fully developed (self-preserving) portion of the flow. Plumes were simulated using helium/air sources in a still and unstratified air environment. Mean and fluctuating mixture fractions were m easured using laser-induced iodine fluorescence. Present measurements exten ded farther from the source (up to 155 source widths) and had more accurate specifications of plume buoyancy fluxes than past measurements and yielded narrower plume widths and different scaled mean and fluctuating mixture fr actions near the plane of symmetry than previously thought. Measurements of probability density functions, temporal power spectra, and temporal integr al scales of mixture fraction fluctuations are also reported.