Airfoil design on unstructured grids for turbulent flows

An aerodynamic design algorithm for turbulent hows using unstructured grids is described. The current approach uses adjoint (costate) variables to obt ain derivatives of the cost function, The solution of the adjoint equations is obtained by using an implicit formulation in which the turbulence model is fully coupled with the flow equations when solving for the costate vari ables. The accuracy of the derivatives is demonstrated by comparison with f inite difference gradients, and a few sample computations are shown. Recomm endations on directions of further research into the Navier-Stokes design p rocess are made.