Nozzle Orientation Effects on the Turbulent Structure of Submerged Twin Jets

Abstract

Nozzle orientation effects on the turbulent structure of submerged twin jets were investigated experimentally. The twin jets were offset from the free surface by the ratio, h/d = 2, where h is the offset height displacement and d is the nozzle’s hydraulic diameter. The experiments were conducted using a pair of rectangular nozzles having an aspect ratio of 3, oriented in both the minor and major axes. The Reynolds number based on the jet exit velocity and nozzle hydraulic diameter was maintained at 4622. The results show a 74% increase in the attachment length for the nozzle oriented in the major axis relative to the minor. The streamwise velocity at the free surface accelerated at a 58% higher rate for the minor axis orientation compared to that of the major axis. The joint probability density function show a dominance of the fast streamwise fluctuation in the generation of the Reynolds shear stress.