涡轮负荷增加会强化激波结构，进而致使涡轮内部流动损失显著增加。探明高膨胀比涡轮内部激波导致的流动损失机制和规律对涡轮性能优化设计至关重要。开展高膨胀比涡轮内部关键流动结构损失定量分析的熵产识别方法研究，并基于该方法探讨某型自主开发高效增压器的高膨胀比涡轮流动损失分布特征和流动机理。研究表明，设计点工况下喷嘴内激波诱导二次流损失占涡轮总损失的80%，其中泄漏流和其他主要二次流结构在各工况下均为主导损失。膨胀比从2.8增加至4.0，泄漏流损失降低至38%，但激波损失占比从0.4%急剧增加至12.4%。基于上述损失规律与机制，结合涡轮性能的响应面代理模型，构建了高膨胀比涡轮局部参数化模型并实现参数化优化设计。结果表明，优化后的涡轮激波强度与诱导损失明显降低，涡轮效率相对提升了1.88%。

Increasing turbine load intensifies shock wave structures, leading to a significant rise in internal flow losses. Unveiling the mechanisms and patterns of flow losses induced by shock waves within high expansion ratio turbines is critical for turbine performance optimization. An entropy production based method was put forward for quantitatively identifying key flow structure losses in high expansion ratio turbines, and exploring the flow loss distribution and mechanisms of an in-house developed high-efficiency turbocharger turbine. The study reveals that secondary flow losses induced by shock waves account for 80% of total losses. The leakage flow and secondary flow structures are the dominated factors of loss in all operating conditions. The expansion ratio increases from 2.8 to 4.0, leakage flow losses decrease to 38%, while the proportion of shock wave losses sharply rises from 0.4% to 12.4%. Based on the above mentioned loss laws and mechanisms and combined with the response surface model of turbine performance, a parameterized model was constructed and parametric optimization design was achieved. The results show that the optimized turbine exhibits a significant reduction in shock wave intensity and induced losses, while the turbine efficiency improves 1.88%.