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Structure of Round, Fully Developed, Buoyant Turbulent Plumes.

pdf icon Structure of Round, Fully Developed, Buoyant Turbulent Plumes. (919 K)
Dai, Z.; Tseng, L. K.; Faeth, G. M.

Journal of Heat Transfer, Vol. 116, No. 2, 409-417, May 1994.


National Institute of Standards and Technology, Gaithersburg, MD


fire plumes; tests; mixing; experiments


An experimental study of the structure of round buoyant turbulent plumes was carried out, emphasizing conditions in the fully developed (self-preserving) portion of the flow. Plume conditions were simulated using dense gas sources (carbon dioxide and sulfur hexafluoride) in a still air environment. Mean and fluctuating mixture fraction properties were measured using single-and two-point laser-induced iodine fluorescence. The present measurements extended farther from the source (up to 151 source diameters) than most earlier measurements (up to 62 source diameters) and indicated that self-preserving turbulent plumes are narrower, with larger mean and fluctuating mixture fractions (when appropriately scaled) near the axis, than previously thought. Other mixture fraction measurements reported include probability density functions, temporal power spectra, radial spatial correlations and temporal and spatial integral scales.