Loss classification and review of secondary flow models in gas turbine cascades

Much attention is paid to increasing the efficiency of turbofan engines by increasing the efficiency of the main modules. The aerodynamic efficiency of a turbine depends on the level of total pressure and kinetic energy losses, which are determined by the scale of secondary flows in the channels of the turbine cascades. There are many studies and articles on the topic of secondary flows, in which vortex structures are often given incorrect names. The problem lies in the absence of a unified model of secondary flows and mismatch in the names of the components of secondary flows in adaptation of model descriptions from English to Russian. The purpose of this review article is to consider the existing classifications of losses and the most famous models of secondary flows in turbine cascades, including the Wang model, the Goldstein and Spores model, the Sharma and Butler model, etc. The considered sources of information made it possible to single out the most complete classification of losses, compare with each other the components of secondary flows of various models, describe the mechanism of their occurrence and give the most complete nomenclature of secondary flows in turbine cascades.