Partially Averaged Navier-Stokes (PANS) Method for Turbulence Simulations-Flow Past a Square Cylinder

The partially averaged Navier-Stokes (PANS) approach is a bridging closure model intended for any level of resolution between the Reynolds averaged Navier-Stokes (RANS) method and direct numerical simulations. In this paper, the proposed closure model is validated in the flow past a square cylinder The desired ratio of the modeled-to-resolved scales in the PANS closure is achieved by appropriately specifying two bridging parameters: the ratios of unresolved-to-total kinetic energy (f(k)) dissipation (f(epsilon)). PANS calculations of different bridging parameter values are performed and the results are compared with experimental data and large-eddy simulations. The Strouhal number (S-t), mean/root-mean-square (RMS) drag coefficient (C-D), RMS lift coefficient (C-L), mean velocity profiles, and various turbulent stresses are investigated. The results gradually improve from the RANS level of accuracy to a close agreement with the experimental results with decreasing value of the bridging parameter f(k). Overall, the results indicate that the PANS method clearly satisfies the basic tenets of a bridging model: (i) provides a meaningful turbulence closure at any modeled-to-resolved scale ratio and (ii) yields improved accuracy with increasing resolution (decreasing modeled-to-resolved ratio). [DOI: 10.1115/1.4003153]