PREDICTIONS OF THE STRUCTURE OF TURBULENT, MODERATELY UNDEREXPANDED JETS

A mathematical model capable of predicting the structure of turbulent, underexpanded jets is described. The model is based on solutions of t he fluid flow equations obtained using a second-order accurate, finite -volume integration scheme coupled to an adaptive grid algorithm. Turb ulence within these jets is modelled using a k-epsilon approach couple d to the compressible dissipation rate model of Sarkar et al. (1991a). Comparison of model predictions and experimental data, reported in th e literature, on a number of moderately underexpanded jets demonstrate significant improvements over results derived using the standard k-ep silon approach, and the adequacy of the compressibility corrected turb ulence model for predicting such jets.