Dilution of circular turbulent nonbuoyant surface jets in cross-flows

This paper presents the results of an experimental study on the dilution of circular nonbuoyant turbulent surface jets of diameter d, discharged perpendicularly into relatively deep cross-flows with depth D in the mixing region. The jet velocity was varied from 2.1 to 12.3 times the velocity of the cross-flow. Concentration measurements were carried out as far as x/d = 630, where x is the distance downstream from the nozzle along the cross-flow. Minimum dilutions of about 100 were attained in this mixing region. A general correlation has been developed to predict the minimum dilution in terms of the transformed distance alpha x/d, where a is the ratio of the jet to cross-flow velocity. The concentration profiles in the vertical and the transverse directions were found to be similar. Expressions were developed to describe the growth of the width and thickness of the deflected jets. The effect of submergence of the jet nozzle on the minimum dilution was also investigated.