A NEW ADAPTIVE ALGORITHM FOR TURBULENT FLOWS

A novel adaptive algorithm for turbulent flows introduces a combination of grid embedding and grid redistribution techniques, as appears to be necessary for efficient resolution of the small scales involved in viscous flows. A method for implementing an algebraic (Baldwin-Lomax) turbulence model with unstructured embedded meshes is developed also. The adaptive algorithm is applied to airfoil flow fields at relatively high Re values of order 10(6), and comparisons are made with experimental data. Two airfoil geometries are considered: a single-element NACA 0012 section in both subsonic and transonic flow; and a two-element NLR section in subsonic flow for two distinct flap deflection settings. The latter simulations appear to be the first Navier-Stokes computations presented. Essential flow physics, such as shock boundary layer interactions and small separation bubbles, are "captured" by the new adaptive algorithm with considerable detail. In addition, the algorithm appears to provide flexibility in generating a mesh around relatively complicated geometries, such as multi-element airfoils.