Research Projects

In modern high bypass ratio aircraft engines, the low pressure turbine (LPT) is responsible for driving the fan and compressor stages, thus there is a huge incentive in improving its performance. To accommodate the high bypass ratio, blades acquire large aspect ratios which result in subsonic, low Reynolds number flows in LPTs. As a result, a substantial portion of the flow is highly unsteady and transitional over a LPT, especially on the suction surface. Unsteadiness of the transition process finds its origin in the turbulence associated with wakes shed by upstream blade rows or free stream turbulence (FST) generated in the combustion chamber. Characterizing this transitional flow is a paramount task in engine design especially in design of devices for active flow control. The project proposes to analyze the role of free stream disturbances on the performance of the LPT by measuring the profile loss. A series of direct numerical simulations (DNS) are to be performed for flow over a T106A LPT blade passage using a novel, error-free parallelization method, referred as the NGC scheme. Specifically, the project aims to establish whether the effect of unsteady wakes or FST can be exploited to offer marginal improvements in drag reduction for the LPT.