INCOMPRESSIBLE TURBULENT FLOW AT THE LEADING EDGE OF SWEPT WINGS

摘要

Due to a singularity in the governing threedimensionalturbulent momentum integralequations at the attachment line, low orderinfinite-swept and swept-tapered CFD methodsemploying the viscous-coupling technique havebeen unable to model attachment line transitionor contamination without approximating thedevelopment of the boundary layer immediatelydownstream of a turbulent attachment line. Anexperimental study was therefore conducted toexplore the flow near a turbulent attachmentline, which showed considerable differences tothe numerical approximation. On the basis ofthe experimental data; a modification to thegoverning equations in the attachment lineregion has been proposed and tested.Comparisons with experimental measurementsshow that the proposed numerical model is notonly able to predict the flow to within ±5%, butit also captures the non-monotonic behaviour ofthe momentum thickness, in the vicinity of theattachment line, which has not been reportedpreviously.