PREDICTION OF TURBULENT-FLOW THROUGH A TRANSITION DUCT USING A 2ND-MOMENT CLOSURE

The near-wall, full Reynolds-stress closure of Launder and Shima is em ployed to calculate the three-dimensional turbulent flow through a cir cular-to-rectangular transition duct. The solutions are compared with the recent experimental data of Davis and Gessner. The comparisons rev eal that the computed streamwise velocity and vorticity fields are in remarkable agreement with the measurements. Downstream of the transiti on region, however, the computed Reynolds stresses appear to decay at a much faster rate than observed in the measurements. These results po int to the need for further refinement of Reynolds-stress models to co rrectly predict the relaxation of rapidly strained turbulence towards equilibrium.