A further enhancement of the PANS method for calculations with moving meshes or with transient boundaries

Paper in proceeding, 2015

The Partial Averaged Navier-Stokes (PANS) model changes seamlessly from Reynolds-Averaged Navier-Stokes (RANS) to the direct numerical solution of the Navier-Stokes equations (DNS) as the unresolvedto-total ratios of kinetic energy and dissipation are varied. An efficient use of the PANS method relies on a definition and calculations of resolution parameters. In the standard approach, the integral scale of turbulence is obtained by using resolved turbulence calculated as difference between instantaneous filtered velocity and the averaged velocity field. Such approach is impractical for cases with moving geometries or with transient boundaries and for example, especially for calculations of engines, which will be shown in this paper, due to a long cycle-to-cycle averaging in order to supply the optimum resolution parameter. This paper deals with an alternative approach which doesn't need a time average velocity field.