LARGE EDDY SIMULATION OF FLOW OVER NOZZLE GUIDE VANE OF A TRANSONIC HIGH PRESSURE TURBINE

LARGE EDDY SIMULATION OF FLOW OVER NOZZLE GUIDE VANEOF A TRANSONIC HIGH PRESSURE TURBINE

Fifth generation fighter aircraft engines demand thrust to weight ratios in excess of 8 and moderate Specific Fuel Consumption. This calls for lower weight and higher component efficiencies. To improve turbine efficiency, it is necessary to understand the aerodynamic loss generation mechanism in the flow field. Since most such mechanisms are unsteady in nature, it is often necessary to carry out unsteady analysis of the turbine stage. It is desirable to study the loss generation mechanisms in the stationary Nozzle Guide Vanes (NGVs) and the rotor blades through unsteady analysis. In this paper, NGV of a transonic high pressure turbine has been analysed using Large Eddy Simulation (LES) and the results have been compared with Reynolds Averaged Navier Stokes (RANS) simulations and Unsteady RANS (URANS) simulations. The investigation is focused on the mechanisms of loss generation in the NGV at low Reynolds number condition of 1.5x106 (high altitude low Mach number condition) where shock boundary layer interactions are predominant.