Time-marching throughflow model for predicting axial turbine performances

A time-marching throughflow solver is applied to the off-design performance prediction of axial turbine. The method solves strictly conservative throughflow governing equations and takes into account the main effects of the real blades on the flow via blockage and blade force. An inviscid blade force is expressed from the tangency condition to the blade mean surface, which is updated automatically at every time step. Empirical loss models are proposed in order to compute viscous force effects in the real three-dimensional flow. The time-marching throughflow code is applied to the investigation of the PW E3 transonic high-pressure turbine on design conditions and of a one-stage low-pressure turbine. The results are extensively compared in terms of both operating performance characteristics and detailed flow fields with experimental data and CFD, steady, viscous results to validate the throughflow method.