Shear Layer Breakdown in Compressible Flow.
Final rept. 1 Nov 91-1 Nov 95,
LEHIGH UNIV BETHLEHEM PA DEPT OF MECHANICAL ENGINEERING AND MECHANICS
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This is a final report describing research carried out on the physical processes of breakdown of unsteady boundary layer flows at high Reynolds numbers. The research is relevant to processes occurring in dynamic stall and transition to turbulence and concerns the complex physical processes that can occur when a boundary layer separates from a rigid wall. The results indicate that very complicated responses develop in the surface pressure, in some cases leading to instability. It has been shown how the boundary layer can break down locally and lead to a process of explosive windup into a new vortex structure. The theory appears to be consistent with and explains the breakdowns observed in experiments, as well as direct simulations of turbulent and transitional flows.
- Fluid Mechanics