Direct Numerical Simulation of Swept-Wing Laminar Flow Control Using Pinpoint Suction

Recent investigations of laminar flow control for swept-wing boundary-layer flows provide promising results with respect to crossflow-transition delay using a technique called pinpoint suction. Strong, localized suction through holes accurately positioned with respect to the crossflow-vortex position can directly weaken the growth of secondary instabilities that are responsible for the final laminar breakdown. With our incompressible code N3D extremely resolved grids in wall-normal direction have to be used to obtain numerical convergence. In order to confirm the results with such strong, localized suction, a single suction hole has been simulated in a Blasius boundary layer with the N3D code and additionally with our compressible code NS3D. Results from grid studies carried out for both codes as well as a comparison of the compressible/incompressible results are provided. Incompressible simulations with various pinpoint suction scenarios in the swept-wing flow show the application of successful pinpoint suction. Performance data for both codes focusing on a comparison of the NEC SX-8/SX-9 conclude this report.