Accession Number : AD0673651

Title :   THE MOLECULAR MIXING VELOCITY ALONG THE BASIC SEGMENT OF A TURBULENT JET (O SKOROSTI MOLEKULYARNOGO SMESHENIYA NA OSNOVNOM UCHASTIKE TURBULENTNOI STRUI),

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Prudnikov,A. G. ; Zamyatina,N. A.

Report Date : 31 AUG 1967

Pagination or Media Count : 14

Abstract : The molecular homogeneity of a combustible mixture controls the reaction rate in diffusional combustion, and it is, therefore, the most important parameter in this process. Experiments were made to study the mixing of two concentrical jets and the molecular homogeneity in the mixing zone. A cold air stream containing NaNO3 vapors was discharged into a concurrent stream of hot combustion products generated by the combustion of a gasoline-air mixture. The hot flow had a temperature of 1650-1800K and a velocity in the 65-90 m/sec range. The cold air stream was injected through uninsulated tubes of 10, 4, and 2 mm diameter located concentrically in the hot flow. The cold gas stream at the outlet from the tube had temperatures of 1100-1400K and velocities of 50-240 m/sec. The light intensity of the hot sodium atoms was determined from photographs and correlated with flow parameters to obtain values for the dispersion and the homogeneity of the gas. The dispersion was found to depend not on the jet diameter but only on the velocity ratio. It had a minimum when both jets had equal velocities. It is concluded that the width of the turbulent-molecular mixing zone monotonically changes from a linear law at a velocity ratio of 0.3 to a parabolic law at a velocity ratio of 1. Mixing to molecular homogeneity takes 2-4 times longer than turbulent mixing. (Author)

Descriptors :   (*COMBUSTION, *JET MIXING FLOW), REACTION KINETICS, DIFFUSION, VELOCITY, TURBULENCE, COMBUSTION PRODUCTS, MIXTURES, USSR

Subject Categories : Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE