Numerical studies of a tubulent jet in crossflow

The application of an improved finite-difference solution procedure to the analysis of the flow field due to a turbulent jet in crossflow is presented. The governing time-averaged differential equations are solved by means of an efficient SIMPLEC algorithm. Two difference schemes, namely, power law and second order upwind, for approximating the convection terms are used and compared. Reynolds stresses are calculated by solving the modelled transport equations for the turbulent kinetic energy and its viscous rate of dissipation. Attention is focused on the cases of high and moderate jet-to-crossflow velocity ratio R. This range of conditions is of direct relevance to the studies of VSTOL in transition flight and the dilution zone mixing in gas turbine combustors. Two-dimensional computations of the plane jet case are performed for the flow geometry corresponding to the experiment of Stek and Brandt (1976). The reattachment length and streamline patterns obtained from the calculations agree very well with the experimental data. Three-dimensional computations of the round jet case are made for the flow geometry associated with the recent measurement of Andropoulos and Rodi (1984). The calculated results are presented with the aid of computer graphics. Flow patterns emerging from various profile, contour, and vector plots indicate that the general features of this complex flow situation are well predicted by the present numerical method. The possible causes of quantitiave discrepancies between computed and measured data are discussed. It appears that further refinements of the turbulence model and grid system are most desirable.