非轴对称端壁改善涡轮叶栅流场研究

Investigation of Improving the Turbine Cascade Flow Using Non-axisymmetric Endwall Contouring

以Pack B涡轮平面叶栅为研究对象,采用非轴对称端壁造型方法,以减少涡轮叶栅总压损失为优化目标,进行了涡轮叶栅的非轴对称端壁优化设计,优化后的总压损失减小了11.83%。通过对叶栅的下端壁以及上下端壁进行非轴对称造型并与原型光壁模型进行全叶高流场对比分析表明:非轴对称造型对几乎全叶高的总压损失分布产生影响,大幅减小了20%和80%叶高附近的总压损失,对气流角和下游涡强度的影响局限在近造型壁面侧的30%叶高内。

The optimization design of the non-axisymmetric endwall of turbine cascade was carried out with the turbine blade cascade PackB. The optimization goal is to reduce the total pressure loss of the turbine cascade. After optimization, the total pressure loss decreases by 11.83%. The following conclusions are obtained by flow field comparison with three models, which are respectively cascade with non-axisymmetric contouring in no/one/both side endwall. Non-axisymmetric endwall contouring on one side have effect on the total pressure loss distribution at almost the whole span of blades and greatly reduced the total pressure loss near the 20% and 80% span. However, the influence of the outlet flow angle and intensity of downstream vortex is limited to 30% span near the contouring endwall.