NUMERICAL ANALYSIS OF A FLOW CONTROL SYSTEM FOR HIGH-PRESSURE TURBINE VANES SUBJECT TO HIGHLY OSCILLATING INFLOW CONDITIONS

Abstract Under the prism of introducing pioneering technologies in the propulsive field, the Rotating Detonation Engine (RDE) continuously attracts the Gas Turbine (GT) research community. However, the time-dependent flow conditions from the RDE greatly affect turbine performance, thus reducing the positive impact of Pressure Gain Combustion (PGC) on the overall cycle efficiency. The present numerical work aims at analysing both the impact of a pulsating inflow on the performance of a newly designed high-pressure turbine vane and the effectiveness of a flow control system in governing the oscillations within the vane passage. First, a baseline vane capable to ingest high enthalpy flow at an inlet Mach number of 0.6 is introduced. A total number of 297 samples are generated with different vane's endwalls and airfoil profile. Then, an optimization strategy is performed using steady inflow conditions concentrating on minimizing the vane's loss coefficient. Afterwards, a flow control system is proposed by placing a series of holes in the endwalls of the vane. Air at constant stagnation conditions is injected upstream of vane's leading edge. Unsteady calculations with and without flow control, including similar pulsating conditions from the RDE provide an insight to the generation and evolution of the secondary flow structures inside of the passage. The main outcome of this analysis is that the flow control system intensifies the passage vortices providing less oscillating flow at the vane exit section, which is beneficial for the aerodynamic performance of a subsequent blade row.