Investigation into the influences of the low-speed flows' accuracy on RANS simulations

With the explosive development of the Computational Fluid Dynamics (CFD), many researchers studied accurate Reynolds Averaged Navier-Stokes (RANS) simulations in low-speed flows by analyzing turbulence modeling or high order reconstruction methods. Few people noticed the influence of the accuracy of spatial scheme for low-speed flow on the RANS simulations. In this paper, we conduct a systematic study on this issue. After a verification of our compressible code, the following four numerical tests are conducted: the flat plate, the NACA0012 airfoil, the NACA4412 airfoil, and the backward facing step. Grid convergent results in these cases show that a high level of accuracy at low speeds is beneficial to the steady RANS computations.