Advances in variable geometry turbine aerodynamic technology for gas turbines

Abstract

The variable geometry turbine technology is one of the effective ways to improve acceleration and deceleration characteristics and low-working-condition performance for gas turbines. However, the design of variable geometry turbines is very difficult, and its design point efficiency is always lower than that of fixed geometry turbines. Moreover, regardless of whether the variable vane is open or closed, the turbine efficiency is significantly reduced, which partially offsets the gas turbine cycle benefits caused by turbine variable geometry. In order that the turbine variable geometry technology can be successfully applied to marine and other gas turbines, the research on the high-efficiency variable geometry turbine aerodynamic technology naturally has very realistic significance of national defense and important engineering application prospects. The development of the research about gas turbine variable geometry turbine aerodynamic technology is reviewed in three aspects: variable geometry turbine characteristics, variable geometry turbine endwall flow mechanisms and loss control as well as variable geometry turbine design features. Besides, the existing issues for variable geometry turbine researches are systematically summarized, and the key trends and future research priorities regarding gas turbine variable geometry turbine aerodynamic technology are presented.