Structure of Round, Fully Developed, Buoyant Turbulent Plumes.
Structure of Round, Fully Developed, Buoyant Turbulent
Dai, Z.; Tseng, L. K.; Faeth, G. M.
Journal of Heat Transfer, Vol. 116, No. 2, 409-417, May
Sponsor:National Institute of Standards and Technology,
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.