Partially Averaged Navier–Stokes Formulation of a Two-Layer Turbulence Model

摘要

Partially averaged Navier-Stokes (PANS) is a scale-resolving simulation (SRS) approach wherein a two-equation closure model is suitably adapted for computing unresolved stresses. The objective of the present study is to develop a two-layer PANS closure for improved near-wall simulation capability. In the RANS context, the two-layer turbulence model displays superior near-wall behavior compared with other closures of similar order. Our goal is to adapt these near-wall closure advantages to PANS-SRS model. In the outer region of the PANS two-layer closure, a PANS k-epsilon turbulence model is employed. In the inner layer, an unresolved kinetic energy equation is solved. The eddy viscosity and dissipation are specified using algebraic equations based on known scaling relationships. The proposed model is evaluated in a turbulent channel flow of friction Reynolds numbers in the range of Re tau=180-950. Comparison with DNS data demonstrates that two-layer PANS is potentially an accurate and robust SRS approach.