AERODYNAMIC PERFORMANCE OF PARTIALLY VARIABLE GEOMETRY HIGH-PRESSURE TURBINE

Variable geometry turbine (VGT) technology changes the throat width of turbine guide vane to control the mass flow rate and adjust the operating condition of engine. With the development of variable cycle engine, the demand for VGT technology is getting urgent. In order to overcome the technical difficulties of current VGT technology, including large tip leakage and low adjustment accuracy, the partially variable geometry turbine (partially VGT) is considered as an alternative solution. Based on the original design of the General Electric Energy Efficient Engine ( E3) high pressure turbine, this paper introduces a new structure with half vanes fixed and the other half adjustable. Numerical simulation and theoretical analysis are applied to investigate the effect of partially VGT on the aerodynamic performance of the high-pressure turbine. The results show that: 1) Within the required mass flow range, partially VGT can achieve a larger rotation angle of the guide vane. The guide vane throat width is linearly related to the setting angle, ensuring the accuracy of regulation. 2) Partially VGT has no significant variation with VGT in the fluid mechanism and distribution of the outlet section parameters. 3) Partially VGT can also play a role in controlling turbine power distribution. The above conclusions show that the partially VGT analyzed in this paper can replace the conventional VGT, which will provide a reference for the research on VGT technology.