A Critical Appraisal of Some Current Incidence Loss Models for the Stator and Rotor of a Mixed Flow Gas Turbine

Incidence losses occur when the gas flow angle does not coincide with the blade angle. Several incidence models which are available to the designer are reviewed and a new method of calculating the incidence losses in the stator and rotor of a mixed flow radial turbine is presented. The results from this model have been compared in the case of a mixed flow radial turbine rotor with the results from the other models and with the experimental results for the stator. All the models assume a change in the tangential component of kinetic energy at stator or rotor inlet. It is concluded that none of these models is satisfactory because they do not take into account the flow pattern in the rotor or stator passages.Copyright © 1982 by ASME