SIMULATION OF SEPARATED TRANSONIC AIRFOIL FLOW BY FINITE-DIFFERENCE VISCOUS-INVISCID INTERACTION

Airfoil performance tends to an optimal when transonic and at least mildly separated flow is generated. Therefore, a significant effort has been made to develop computational methods capable of simulating this important class of flow field. However, separated transonic airfoil flow is complex and its accurate and efficient simulation remains quite challenging.;The accuracy and efficiency of the developed viscous and viscous-inviscid interaction programs has been tested and verified by comparison with theory, the results of other boundary-layer and Navier-Stokes computations, and experimental data. Separated transonic flow fields about lifting airfoils are accurately simulated for approximately 1-5% of the cost of a Navier-Stokes simulation of equal resolution. Because efficient viscous and inviscid algorithms are used and the viscous-inviscid interaction converges rapidly, it is expected the new code will also compare favorably with other codes of its type as they become available.;For these reasons, a finite-difference viscous-inviscid interaction program has been developed which is capable of simulating the separated transonic flow about non-lifting and lifting airfoils. This code consists of a new, direct-inverse, finite-difference boundary-layer algorithm coupled with a transonic full-potential airfoil program using new viscous-inviscid interaction algorithms.