Aerodynamic Design And Related Problems Research Of Low Pressure Turbine Of A Large Gas Turbofan Engine

Large turbofan engine as the main power of aircraft and large transport aircraft inthe field of aero-engine occupy an important position is on request of improvingperformance and technique with technological development. Low pressure turbine (LPT)provides necessary power for the fan and low pressure compressor as one of the powerof large turbofan engine, at the same time, LPT’s weight is about one third of the wholeengine. Multi-stage high-load low pressure turbine aerodynamics design should be oneof the ways on solving these problems, and this design idea has been applied to actualaero-engine, and good results has been achieved. Base on this point, the main task ofthis article is to carry out the aerodynamic optimization design work on increasing theaerodynamic performance, and other series researches on low pressure turbinesimultaneously.First of all, this paper gets to understand the main performance parameter, the wayto choose key parameter,3D flow detail and aerodynamic design characteristic of theoriginal low pressure turbine with three level computations of one dimensional design,quasi-three dimensional design, full three dimensional CFD method. And the lowpressure turbine aerodynamic of American Energy Efficient Engine project is discussedwith the one this paper is studied.Secondly, based on protomodel aerodynamic computation, aerodynamic designoptimization was carried out to improve the performance. Because of the limitation oftime, quasi-three dimensional design program and quasi radial lines rotation variablethickness S1stream surface program are chosen as the solver of aerodynamiccalculations optimization respectively. Blade shape construction consists two ways,including Pritchard11parameters geometry model and AutoBlade from numecasoftware package. The aerodynamic optimization results will be computed through fullthree dimensional CFD method.At last, some issues about low pressure turbine aerodynamic design are discussed,including first stage stator using bowed blade with large diffused angle, first stage statorusing little camber balde and effect on overall performance by endwall cooling airinjection with orthogonal experimental design. It’s necessary to find out some methodsto improve the performance of low pressure turbine.