A 3-D unsteady flow computation has been performed for a transonic first turbine stage under the influence of streaks of hot gas exiting the combustion chamber. Realistic flow conditions are obtained by using a non-equal stator-to-rotor pitch, a single-streak/multi-stator channels configuration and periodic boundary conditions. The resulting unsteady shock waves system and the hot streaks migration as well as the shock wave/streak interaction are presented and discussed. In addition, the time-average of the periodic unsteady solution is analyzed and compared with a steady-state computation. The steady-state solution matches the time-averaged one in terms of the pressure field and the maximum stagnation temperature on the rotor blade surface. However, the rotor blade temperature patterns are different with a stronger radial secondary flow present in the time-averaged solution due to the retention of the circumferential streak variations at the stator/rotor interface.

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