Research On The Design Method Of Micro Vane Nozzle

On the micro turbine engine background,this thesis studies the design method of the micro-turbine nozzle,and proposes an improved design project on the vane turbine nozzle of 16cm-scale engine MTE-C.First,researched the influence to the inner flow field and the performance of nozzle by changing vane angle distribution and axis-to-radial scale ratio through the three-dimension viscous numerical simulation, optimized of vane angle distribution of turbine nozzle as similar scale: the performance of nozzle is determined mainly by vane angle distribution of root, the linear design and lower-concave design vane angle distribution excels other two designs in terms of performance and field flow;as the non-dimensional parameter B which can denote axis-to-radial scale ratio increasing, the performance of nozzle increase first,and then decrease,the optimal value of B is about 1.9.Secondly, researched flow field and the performance of nozzle of 16cm-scale engine MTE-C by numerical simulation, and the reasons which cause the low performance are got by flow field analysis,based on that and optimal vane angle distribution, the vaned turbine nozzle is improved, the performance of nozzle increases greatly,the total pressure recovery increases to 0.918 from 0.909,the speed coefficient increases by 2.45%,as well as the quality of nozzle exit.The result of numerical simulation to turbine stage shows that the performance of turbine which uses the improved vane nozzle increases greatly, the efficiency at design point increases to 84.2% from 70.9%,the wheel flange power increases to 166kJ/kg from 139kJ/kg.Thirdly,we simulate the performance of both the original and improved engines,the engine thrust at design point increases to 405N from 349N,while the specific fuel consumption decreases to 0.037 g/(N·s) from 0.044 g/(N·s). We also test the performances of MTE-C with new turbine vane nozzle and exhaust nozzle.the result shows that the performance increases both in turbine efficiency and the whole engine.At last, optimized the exit angle of nozzle and axis-to-radial scale ratio in MTE-C, the efficiency and the wheel flange power increase to 89.3% and 175kJ/kg respectively,the current that the performance of nozzle influenced by axis-to-radial scale ratio is coincident with what has got in former research,only vary in optimal vaule of B.