小型部分进气亚声速涡轮流动损失研究及优化

为拓展某小型部分进气亚声速涡轮的应用能力,要求进一步提高其气动性能。使用Numeca商用计算流体力学软件建立了原型部分进气涡轮流道的全环域网格,进行了流场的粘性数值仿真,通过与相同叶型全周进气式涡轮的流场对比分析,揭示了部分进气式涡轮的流动机理和流动损失分布规律。在流场结构研究的基础上,对原型涡轮的动叶进行了改型优化,将动叶叶型由原来的纯冲击式叶型改为略带反力度的叶型,流场仿真结果表明涡轮效率提高了5个百分点。通过对改型前后2种部分进气式涡轮气动参数分布情况的对比分析,表明略带反力度的动叶叶型能有效减小部分进气式涡轮非进气扇区动叶通道内的回流损失,对提高涡轮性能有利,可为同类涡轮的气动设计提供参考。

Research and optimization for flow loss of a small partial admission subsonic turbine

In order to expand the application of a small partial admission subsonic turbine,its aerodynamic performance is required to be improved further.The commercial use CFD software Numeca is used to build an entire annular domain grid of the prototype partial admission turbine flow path and conduct a viscid numerical simulation of flow field.In contrast with the flow field of the full admission turbine with the same blade profile,the flow loss distribution and flow mechanism of the partial admission subsonic turbine were revealed.On the basis of research on flow field,the moving blade of the prototype turbine was remodeled and optimized,changing it from impulse shape to slight reaction shape.The result of the flow field simulation indicates that the turbine efficiency is increased by 5％.The comparison and analysis of aerodynamic parameter distributions of the two partial admission turbines show that the blade shape of the slight reaction can reduce backflow loss in the flow path in non-admission fan-type area of the partial admission turbine,which is beneficial to improvement of turbine performance.This study can offer a reference for the aerodynamic design of the same kind of turbines.