Prediction of Tip-Leakage Losses in Axial Turbines

Existing methods for predicting the tip-leakage losses in turbomachinery are based on a variety of assumptions, many of which have not been fully verified experimentally. Recently, several detailed experimental studies in turbine cascades have helped to clarify the physics of the flow and provide data on the evolution of the losses. The paper examines the assumptions underlying the prediction methods in the light of these data. An improved model for the losses is developed, using one of the existing models as the starting point.