Hot Streak Clocking Effects in a 1-1/2 Stage Turbine

Abstract

Experimental data has shown that combustor hot streaks can lead to pressure side “hot spots” on first-stage turbine rotor blades. Previous numerical studies have confirmed that unsteady Navier-Stokes procedures can be used to predict the rotor pressure surface temperature increase associated with these combustor hot streaks, and suggest that second-stage turbine stators can also be subjected to increased surface temperatures. In the current investigation, two-dimensional unsteady Navier-Stokes simulations have been performed to study the effects of combustor hot streak position (or clocking) on the temperature distributions along first-stage rotor and second-stage stator airfoils. The predicted results indicate that if the hot streak is positioned such that it impinges upon the first-stage stator, then the suction surfaces of the rotor and second-stage stator attain higher time-averaged temperatures than the pressure surfaces. If the hot streak is positioned such that it does not impinge upon the first-stage stator, then the pressure surfaces of the downstream blades reach higher time-averaged temperatures than the corresponding suction surfaces.