A Simple Method for Estimating Secondary Losses in Turbines at the Preliminary Design Stage

Reasonably accurate estimation of losses at an early design stage plays an important part in the success of a turbine design. Although various computational methods exist for estimating the profile loss, for secondary losses which are equally important, designers still rely on emprical estimates. A method has been developed for estimating the secondary flow and secondary losses within an axial turbine cascade. It is assumed that the inlet boundary layer is convected into a loss core within the blade passage while extra loss has been generated due to the secondary kinetic energy and a new boundary layer that is developing on the end wall. The method has been applied to various test cases and the results show that the basic approach is reliable.Copyright © 1992 by ASME