Large Eddy Simulation of Compressible Transitional Cascade Flows

(The Behaviors of Transitional Boundary Layer on a Blade Surface)

Abstract

Large-eddy simulation of compressible transitional flows in a low-pressure turbine cascade is performed by a 6th-order compact finite-difference and 10th-order filtering method. Numerical results without free-stream turbulence and those with about 5% free-stream turbulence are compared. Based on the computed results, detailed investigations are presented on the effects of the free-stream turbulence on the boundary layer transition, and on the behavior of the pressure waves that originate near the trailing-edge along with the effects on the separation/transition of the boundary layer. Also, based on Snapshot Proper Orthogonal Decomposition (POD) Analysis, dominant behaviors of the transitional boundary layers are investigated.