Computation of turbulent horseshoe vortex flow past swept and unswept leading edges

Three dimensional turbulent horseshoe vortex flow past strut/endwall configurations having both unswept and 45-degree swept leading edges is studied by numerical solution of the compressible Reynolds-averaged Navier-Stokes equations. The Cartesian form of the equations is transformed to a general nonorthogonal coordinate system which is fitted to the geometry of interest and then solved using a consistently-split linearized block implicit (LBI) algorithm. The turbulence model and computational mesh provides for resolution of the viscous sublayer and employs an isotropic eddy viscosity based on solution of the turbulence kinetic energy equation and a specified length scale. Although no flow measurements are available for the region near the leading edge, predictions of the horseshoe vortex formation near the leading edge are in qualitative agreement with flow visualization studies of similar flows. Predictions of the relatively weak secondary flow in the corner region well downstream of the unswept leading edge do not agree with available measurements, and this is believed to be the result of numerical truncation error and/or inadequacy of the turbulence model.