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, how to effectively couple an RDE with high-pressure turbine (HPT) stages is still debated. In fact, 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 analyzing 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 of ingesting high enthalpy flow at an inlet Mach number of 0.6 is introduced. A total number of 297 samples are generated by varying the 18 geometrical parameters that characterize the vane’s endwalls and airfoil profile with the help of a Latin hypercube sampling method. An optimization strategy is then performed under steady inflow conditions to minimize the vane’s loss coefficient, thereby determining the final geometry of the new vane. In the second part of the work, 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 the vane’s leading edge. Unsteady calculations with and without flow control, including similar pulsating conditions from the RDE, provide an insight into the generation and evolution of the secondary flow structures inside 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.
