Implicit Large Eddy Simulation of a Low-Pressure Turbine Cascade with resolved Endwall Boundary Layers

Abstract

The following thesis presents a large-eddy simulation approach for predicting the flow inside a low-pressure turbine cascade. A high-order discontinuous Galerkin method is used as an efficient way of obtaining the desired results. The turbine profile under investigation is the MTU T161, placed as a prismatic blade between diverging endwalls. In terms of isentropic flow quantities, the considered operating condition lies at an exit Mach number of M2,is = 0.6 and an exit Reynolds number of Re2,is = 90, 000. The retained numerical solution is validated against available measurements of the cascade at the defined operating condition. Additionally, a comparison with data obtained from a RANS calculation is drawn. With the intention of reducing the computational expense of the undertaken approach, a further calculation is run, on behalf of which an unstructured mesh approach is introduced. Finally, a closer resemblance of real engine conditions is targeted by generating unsteady inflow disturbances with the use of moving cylindrical bars upstream of the cascade.