Effect of inlet conditions on endwall secondary flows

Exit combustor flow and thermal fields entering downstream stator vane passages in a gas turbine engine are highly nonuniform. These flow and thermal fields can significantly affect the development of the secondary flows in the turbine passages attributing to high platform heat transfer and large aerodynamic losses. An analysis is presented of the effects of both the temperature and velocity profiles on the secondary flows in the endwall region of a first-stage stator vane geometry. These effects were assessed using the predicted flowfield results from computational fluid dynamics (CFD) simulations. Prior to using the predictions, these CFD simulations were benchmarked against flowfield data measured in a large-scale, linear, turbine vane cascade, Good agreement occurred between the computational predictions and experimentally measured secondary hows. Analyses of the results for several different cases indicate the stagnation pressure gradient is a hey parameter in determining the character of the secondary flows.