DNS of laminar-to-turbulent transition over a cooled/heated supercritical wing*

Effects of cooling and heating supercritical airfoil surface on laminar-to-turbulence transition and drag are investigated through high-fidelity DNS. The DNS is performed by our high-order structured-grid-based flow solver and state-of-the-art supercomputer Fugaku, with the number of grid points of approximately 3.1 billion. Through the DNS, it is found that airfoil surface cooling induces delayed transition while heating promotes the transition. Moreover, we clarify that the transition process over the supercritical wing is the same as the traditional one over a flat plate observed in prior DNS, while cooling airfoil surface cooling makes the Λ vortices sharp and extended, which results in the downstream shifted location of the transition. Furthermore, the resultant friction drag is reduced by cooling the airfoil surface due to the delayed transition and decreased viscosity.