Effect of small vortex-generators on scalar mixing in the developing region of a turbulent jet

This paper investigates the effect of small tabs placed at the exit plane o f an axisymmetric smooth contraction on passive scalar mixing in a slightly heated turbulent jet. It is shown that the presence of tabs profoundly dis torts the jet flow field and consequently modifies the scalar mixing charac teristics significantly. Tabs cause the mean temperature to decrease more r apidly with downstream distance, implying an increased mixing rate. Further more, it is found that two tabs distort the jet from the axisymmetric state more dramatically than four tabs. (C) 1999 Elsevier Science Ltd. All right s reserved.