Similarity Solution for a Turbulent Round Jet

Abstract

Turbulent round jets are encountered in a variety of forms in engineering and natural systems. Among the similarity solutions, Wollmers and Rotta used the self-preserving property of a turbulent jet and developed a k-kl model to solve the turbulence closure problem. So obtained similarity solutions for a round jet by assuming a velocity profile in the form of a gaussian error function. This assumption is very restrictive because it does not allow the shape of the velocity profile to evolve from the governing equations, but compels them to accommodate the assumed velocity profile. Paullay et al. used the principle of moving equilibrium, to derive a similarity solution for plane and radial jets. Their solution is not general enough to include the round axisymmetric jets, which are most commonly met in engineering practice, because the governing equations used are not applicable to round jets. The authors followed essentially the method by Paullay et al. and derived a similarity solution for the turbulent, axisymmetric round jet, without using any assumptions about the shape of the velocity profile. In this short paper, they present the results of calculations based on the similarity solution and compare these results with experimental data and 2-D numericalmore » computations obtained with a commercial package. The agreement of the results and experiments shows that the similarity solution yields accurate results.« less