The near-wall, full Reynolds-stress closure of Launder and Shima is employed to calculate the three-dimensional turbulent flow through a circular-to-rectangular transition duct. The solutions are compared with the recent experimental data of Davis and Gessner. The comparisons reveal that the computed streamwise velocity and vorticity fields are in remarkable agreement with the measurements. Downstream of the transition region, however, the computed Reynolds stresses appear to decay at a much faster rate than observed in the measurements. These results point to the need for further refinement of Reynolds-stress models to correctly predict the relaxation of rapidly strained turbulence towards equilibrium.
Bibliographical noteFunding Information:
This research was supported by a grant from the Tennessee Valley Authority, monitored by W. R. Waldrop, and by the Office of Naval Research, Grant NOOO14-91-J-1204, monitored by L. P. Purtell. Tabulated experimental data were kindly provided by D. O. Davis. The calculations were carried out on the Cray XMP/216 at the Idaho National Engineering Laboratories and the Cray-C90 at the San Diego Supercomputer Center.