Outflow Boundary Conditions for Spatial Navier-Stokes Simulations of Transition Boundary Layers

摘要: For numerical simulations of the spatially evolving laminar-turbulent transition process in boundary layers using complete Navier-Stokes equations, treatment outflow requires special attention. The disturbances must pass through this without causing reflections that would significantly alter flow upstream. In paper, we present various methods to influence disturbed downstream region interest, such disturbance level at is reduced, and hence possibility minimized. To demonstrate effectiveness techniques near boundary, fundamental breakdown a strongly decelerated layer simulated. Our results show most effective method suppress vorticity within so-called "relaminarization zone." suppression gradually imposed zone by means weighting function. enforced decay leads practically dissipation any fluctuating component. Most importantly, technique causes only negligible upstream effect. "relaminarized" boundary-layer then passes significant reflections.