Validation of a CFD Methodology for Variable Speed Power Turbine Relevant Conditions

Analysis tools are needed to investigate aerodynamic performance of Variable-Speed Power Turbines (VSPT) for rotorcraft applications. The VSPT operates at low Reynolds numbers (transitional flow) and over a wide range of incidence. Previously, the capabilities of a published three-equation transition and turbulence model in predicting the transition location for three-dimensional heat transfer problems were assessed. In this paper, results are presented of a post-diction exercise using a three-dimensional flow in a transonic linear cascade comprising VSPT blading. The measured pressure distributions and integrated spanwise total pressure losses and flow angles for two incidence angles corresponding to cruise (i = +5.8°) and takeoff (i = –36.7°) were used for this study. For the higher loading condition of cruise and the negative incidence condition of takeoff, overall agreement with data may be considered satisfactory but areas of needed improvement are also indicated.