An Experimental Investigation of Ducted, Reactive, Turbulent Jet Mixing with Recirculation

Abstract

Abstract : An experimental investigation of ducted, two stream, subsonic, reactive, turbulent jet mixing with recirculation was conducted. A primary jet of air at a mass flow rate of 0.075 lb/sec and velocity of 700 ft/sec was surrounded by an outer, low velocity, hydrogen stream. Data were obtained with hydrogen-air ratios of 0.143 and 0.107. The duct-to-inner nozzle diameter ratio was ten. Radial distributions of hydrogen mass fraction, mean axial velocity, turbulence intensity, and total pressure as well as axial distributions of wall hydrogen mass fraction and wall static pressure are presented for axial stations from one-half to five duct diameters from the nozzle exit plane. Comparison of the experimental data with calculations assuming frozen or equilibrium chemistry indicate that he measured velocity, pressure, and composition data are, in general, self-consistent. The maximum turbulent intensities which occurred in the center of the mixing layer and within the recirculation eddy were very high having values of 20 percent of the jet exit velocity. The velocity and composition field indicate that, while and mixing in the reactive flow field is slower than for the nonreactive case, the reaction had little effect on the size and location of the recirculation zone within the mixing duct.