Results from the Fifth AIAA Drag Prediction Workshop obtained with a parallel Newton-Krylov-Schur flow solver discretized using summation-by-parts operators

Abstract

We present the solution of the test cases from the Fifth AIAA Drag Prediction Workshop computed with a novel Newton-Krylov-Schur parallel solution algorithm for the ReynoldsAveraged Navier-Stokes equations coupled with the Spalart-Allmaras one-equation turbulence model. The algorithm employs summation-by-parts operators on multi-block structured grids, while simultaneous approximation terms are used to enforce boundary conditions and coupling at block interfaces. Two-dimensional verification and validation cases highlight the correspondence of the current algorithm to established flow solvers as well as experimental data. The common grid study, using grids with up to 150 million nodes around the NASA Common Research Model wing-body configuration, demonstrates the parallel computation capabilities of the current algorithm, while the buffet study demonstrates the ability of the solver to compute flow with substantial recirculation regions and flow separation. The use of quadratic constitutive relations to modify the Boussinesq approximation is shown to have a significant impact on the recirculation patterns observed at higher angles of attack. The algorithm is capable of efficiently and accurately calculating complex three-dimensional flows over a range of flow conditions, with results consistent with those of well-established flow solvers using the same turbulence model.