NUMERICAL-SIMULATION OF TURBINE HOT-SPOT ALLEVIATION USING FILM COOLING

Experimental data have shown that combustor hot streaks can lead to pressure side ''hot spots'' on first-stage turbine rotor blades. In previous numerical studies, it has been shown that unsteady Navier-Stokes procedures can be used to predict the rotor pressure surface temperature increase associated with these combustor hot streaks. In the current investigation, similar two-and three-dimensional unsteady Navier-Strokes simulations have been performed to demonstrate the use of numerical tools in the optimization of film cooling configurations. In this study, the addition of prudently placed film cooling holes along the rotor pressure surface is shown to significantly diminish the adverse effects of the hot streak. Using a two-dimensional Navier-Stokes procedure, a parametric study was performed to determine the impact of the location of the film cooling holes, fluid injection velocity, and fluid injection angle on the time-averaged rotor surface temperature. The experience gained from these two-dimensional simulations was then applied to a series of three-dimensional simulations in which the effects of the film cooling hole distribution on the rotor pressure surface temperature were studied. The results of these simulations indicate that computational procedures can be used to design feasible film cooling schemes which eliminate the adverse effects of combustor hot streaks.