Navier-Stokes analysis of three-dimensional S-ducts

Abstract

Full three-dimensional Navier-Stokes computational results are presented for compressible flows within nondiffusing and diffusing S-ducts. The present study provides an understanding of the performance characteristics of typical S-ducts with attached and separated flows, and provides a frame of reference for future computational fluid dynamic studies of internal flows with strong secondary flows. The predicted results, which were obtained using both H- and O-grids, are compared with the experimental wall pressures, static and total pressure fields, and velocity vectors. In addition, computed boundary-layer thickness, velocity profiles in wall coordinates, and skin friction values are presented. The inviscid contributions to the secondary flows are quantified. The S-duct entrance Mach number was 0.6, and the Reynolds number was 1.76 x 10 6 based on the upstream duct diameter. A = A+ = Cf — Cps = Cpt = D = k = Ps = Pt = Q = Re S = Tw = Ue = Ut = u+ = v w x y+