Unsteady performance of an HP turbine stage optimised for steady flow conditions

The article is focused on the examination of the unsteady performance of an HP turbine stage the blades of which were previously optimised for steady flow conditions. For the purpose of this examination, two pairs of initial and optimised stages of comparable output parameters were selected. The results have revealed that the modification of the blade profile in the optimisation process made the rotor blades more vulnerable to unsteady flow fluctuations, which eventually cancelled a considerable part of the stage efficiency gained from the steady flow optimisation.