Influence of Stator Clocking on the Unsteady Three-Dimensional Flow in a Two-Stage Turbine

Abstract

To give insight into the influence of the clocking and the stator–rotor interaction, the unsteady three-dimensional (3D) flow through a two-stage turbine is simulated numerically, using a time marching Navier–Stokes computer code with a sliding mesh approach. A stator clocking is applied to the second stator vane over several circumferential positions. The numerical results are compared with the experimental one to check the availability of the code. Clocking effects on the turbine performance, wake trajectories, and outlet flow field are focused. A relative efficiency variation of about 0.52% is concluded among clocking positions. A link between the turbine efficiency and the wake trajectories on the midspan is shown based on the presented clocking analysis in the 3D unsteady flow field. The detailed illustration of the outlet flow field shows that the influence of the clocking at the outlet is focused on the temperature distribution.