本文对某型部分冠低压涡轮叶冠泄漏流动的流动特征和损失进行了分析，探讨了部分冠容腔内的损失机理，对部分冠叶冠结构进行了气动优化和结构减重两个阶段的优化设计，分析了气动优化设计前后流动和损失的变化。结果表明叶冠容腔出口腔内存在严重的主流入侵现象与周向泄漏；由此引发的掺混损失使得出口腔内的损失最为显著，占叶冠容腔总损失的80%；优化后的叶冠缘板结构能够有效消除周向泄漏，抑制主流入侵从而提升涡轮级性能0.54%；合理设计叶冠结构可以实现相比原型部分冠减重6.1% 的同时提升0.48% 涡轮级效率。

In this paper, the flow characteristics and losses of the leakage flow in a partial shrouded low-pressure turbine are analyzed. The loss mechanism in the shroud cavity is discussed. The shroud geometry has experienced two stages of aerodynamic optimization and weight optimization. The changes of flow characteristics and loss before and after the aerodynamic optimization are analyzed. The result shows that there is serious mainstream ingress and circumferential leakage in the exit cavity; The resultant mixing loss makes the loss in the exit cavity the most significant, accounting for 80% of the total loss inside the shroud cavity; The optimized shroud geometry can effectively eliminate the circumferential leakage, suppress mainstream ingress, improving turbine stage performance by 0.54%; Reasonable design of the shroud geometry can sustain the turbine stage efficiency improvement by 0.48% and obtain a weight reduction by 6.1% compared to the datum shroud geometry.