Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence

The flow at low Mach numbers and high angles of attack over axisymmetric configurations is not symmetric. mechanism that triggers the asymmetry a combination global (temporal) instability convective (spatial) instability. This latter caused by roughness other geometrical imperfections, which lead to roll angle dependent forces. these conditions has complex vortex sheet structure, with two or three different regions. An accurate simulation means Computational Flow Dynamics (CFD) thus very challenging, many researchers have therefore employed Large Eddy Simulation (LES) codes. study demonstrates Unsteady Reynolds Averaged Navier-Stokes (URANS) methods are suitable alternative, if Scale Adaptive (SAS) used. method capable capturing main features, provided fine meshes, achieve similarity between meshed geometry real object, small-time steps It also demonstrated that, using URANS in SAS, strong differences local forces depending on surface model obtained, result coincides several wind tunnel tests.