NUMERICAL SIMULATION OF A SIMULATED FILM COOLED TURBINE BLADE LEADING EDGE INCLUDING CONJUGATE HEAT TRANSFER EFFECTS

A conjugate numerical method was used to predict the normalized "metal" temperature of a simulated turbine blade leading edge. This computational study was done in conjunction with a parallel effort to experimentally determine normalized metal temperature, i.e. overall effectiveness, using a specially designed model blade leading edge. Also examined in this study were adiabatic models which provided adiabatic effectiveness results. Two different film cooling configurations were employed. The first configuration consisted of one row of holes centered on the stagnation line. The second configuration had two additional rows located at +/- 25 degrees from the stagnation line. These simulations were run at two different blowing ratios, M = 1 and M = 2. The coolant to mainstream density ratio was 1.5. The computational simulation was conducted using the FLUENT code using the realizable k-epsilon turbulence model and with grid resolution within the viscous sublayer. Adiabatic effectiveness distributions were predicted well by the computational simulations, except for localized areas near the holes. Predictions of overall effectiveness were higher than experimentally measured values in the stagnation region, but lower along downstream section of the leading edge. Reasons for the differences between computational predictions and experimental measurements were examined.