"A Wall-Modeled RANS-SA Approach for Unstructured Grids"

2 December 2022
12:00 pm to 1:00 pm
"A Wall-Modeled RANS-SA Approach for Unstructured Grids"
Carmen-Ioana Ursachi
Graduate Student, MIT ACDL

Abstract:   In this talk, a wall model based upon a modified version of the Spalart-Allmaras turbulence model is presented. Unlike typical wall models, this method avoids the need to query the interior solution by utilizing solution information solely at the boundary. By avoiding the need to probe the interior solution, this wall model is well-suited for unstructured grids and is adjoint consistent - key features that enable mesh adaptation and higher-order finite element methods. This wall-modeling method is formulated to lessen the grid resolution requirements near the wall by driving the eddy viscosity to an approximately constant, non-zero value near the wall, forcing the velocity profile to be nearly linear. Using this new wall-modeling method, the impacts of output-based mesh adaptation and higher-order methods are assessed and compared to standard wall-resolved RANS-SA. It is shown that this new wall-modeling approach results in accurate predictions of quantities of interest such as aerodynamic coefficients, surface pressure, and skin friction compared with wall-resolved RANS-SA.