DPW-8/AePW-4: Transonic Shock Buffet URANS and LBM/VLES Simulations of the ONERA OAT15A Airfoil

The study presents the numerical characterization of the transonic shock buffet phenomenon on the ONERA OAT15A supercritical airfoil using unsteady Reynolds-averaged Navier-Stokes (URANS) and lattice-Boltzmann method/very large eddy simulation (LBM/VLES) modeling approaches; in support of the joint DPW-8/AePW-4 Buffet Working Group (Test Case 1). A total of ten angles of attack at both pre- and post-buffet onset conditions were studied at freestream Mach and Reynolds numbers of 0.73 and 3M, respectively. URANS simulations were conducted using the SU2 solver, while LBM/VLES computations were performed with SIMULIA's PowerFLOW solver. Numerical results were analyzed based on the integral forces and moments, mean surface pressure coefficient distribution, and pressure fluctuations on the airfoil suction surface, and compared to existing experimental data. A detailed sensitivity analysis was conducted to study the effects of grid topology and resolution, numerical schemes, and turbulence modeling on the accuracy of the numerical results. The findings presented herein provide valuable insight and guiding practices for both SU2 and PowerFLOW solvers to accurately predict transonic shock buffet phenomena. This knowledge will be applied in a future effort to solve Test Case 2, which involves full-aircraft simulations, as part of the Buffet Working Group.