PANS simulations of turbulent separated flow over a wall-mounted hump Conference Paper uri icon

abstract

  • 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. The partially averaged Navier-Stokes (PANS) method of turbulence closure is investigated to simulate flow separation over a wall-mounted hump. The PANS bridging model varies between direct numerical simulations (DNS) and Reynolds-averaged Navier-Stokes (RANS) method by adjusting the ratios of the unresolved-to-total turbulent kinetic energy (fk), and the unresolved-to-total energy dissipation rate (f) between 0 and 1. Preliminary RANS simulations using the SST turbulence model produced longer recirculation bubbles due to lower Reynolds stresses and eddy viscosity computed within the separation region, reconfirming previously cited observations. The PANS method is run holding fk = 0.2 and f = 1. Initial simulations are set up without an unsteady, turbulent inlet profile, and comparisons with experiment show that even with coarse meshes, reasonable agreement in terms of reattachment location can be made. For steady inflow conditions, there is a range of mesh resolutions outside of which predictions of the bubble size start to deviate significantly from experiment. For finer meshes, various unsteady inflow strategies are analyzed, and the standard recycling-rescaling method of turbulence generation is found to work best with this setup. Quantitative comparisons of mean velocity profiles, Reynolds stresses, skin friction and pressure are made with experiment for all cases, to evaluate the quality of the separated flow simulations.

published proceedings

  • 22nd AIAA Computational Fluid Dynamics Conference

author list (cited authors)

  • Higuera, D., Sekhar, S., Mansour, N. N., Razi, P., & Girimaji, S.

complete list of authors

  • Higuera, D||Sekhar, S||Mansour, NN||Razi, P||Girimaji, S

publication date

  • January 2015