Analysis of Stator-Stator Clocking in a Transonic Turbine
Clocking, i.e. the relative pitch-wise positioning between two successive vanes with the same amount of airfoils, has been demonstrated to bring potential aero-thermal benefits in several recent studies. Indeed, across a vane pitch, a variation of both time-averaged and time-resolved quantities is induced. In order to advance the knowledge on clocking, this 2D numerical investigation proposes a complete description of the unsteady flow field at midspan in a one and half stage turbine at four clocking positions. Mechanisms of migration across the rotor of the first vane wake and its interaction with the second vane has been put into evidence. Additionally, the behavior of the shock system between the rotor and the second stator is assessed indicating effects due to the clocking, like the similar the shape of the shock system when rotor/2nd stator are in the same relative positions.