Numerical Effects of Flux Calculation Schemes for Unstructured Grid Turbulent Flow Simulations

Author(s)

Maia de Oliveira Carvalho, Leonardo Motta ; da Silva, Ricardo Galdino ; Azevedo, Joao Luiz F.

• Document type: Journal article
• Source: AIAA AVIATION 2019 FORUM; v. N/A, p. 25-pg., 2019-01-01.

Abstract

The present work is concerned with the investigation of the effects of some implementation issues which are present in an in-house unstructured grid CFD code, but which are representative of aspects which are relevant, in general, for unstructured mesh codes. The focus is on the effects over aerospace flow calculations of the use of limiters for the turbulent variables and of the entropy correction terms that are typical to many upwind schemes. The formulation in the code uses the Reynolds-averaged Navier-Stokes (RANS) equations with appropriate turbulence models. In the present study, the SST turbulence closure is used. The equations are discretized by a finite volume method for general unstructured grids. Spatial discretization uses the Roe approximate Riemann solver and time discretization employs an implicit method, solved with a symmetric Gauss-Seidel relaxation approach. Three test cases are used, namely, a zero pressure gradient flat plate flow, the flow over at a NACA 4412 airfoil, and the flow over a 3-D bump in a channel. Several levels of mesh refinement are addressed in each test case. Results are compared to data available in the Turbulence Modeling Resource (TMR) website. Results indicate that some options of numerical parameters yield calculations with a strong dependence on the mesh refinement. (AU)

• FAPESP's process: 13/07375-0 - CeMEAI - Center for Mathematical Sciences Applied to Industry
• Grantee: Francisco Louzada Neto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC