Near-Wall Subgrid Mixing Model for Film-Cooled Surfaces

摘要

We propose a computationally affordable and quantitative modeling approach to compute the wall temperature of multirow film cooling configurations common in gas turbine applications. In lieu of a fully resolved simulation of a large array of individual jets in crossflow, a near-wall subgrid mixing model is employed to capture the aggregate effect of the injected momentum and energy at the wall. The wall boundary condition is formulated in a continuum, and not at discrete injection sites as the structure of individual jets is below the scale of the grid. A mass, momentum and energy conserving, continuum, wall boundary condition is presented. This boundary condition is coupled with a new model where the mixing is distributed over a finite film thickness by adding source terms to the multi-specie Reynolds Averaged Navier-Stokes Equations. The source terms are based on the concentration of unmixed jet momentum and energy species that are introduced with the cooling flow and tracked with additional transport equations. The model formulation is described and results are compared to experimental data.