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对向心透平叶轮内部复杂流动在级环境下进行了全三维黏性数值模拟,结合拓扑学原理分析了设计工况和非设计工况下其内流动分离及各种涡系发展的演变过程,初步建立了向心透平叶轮内的旋涡模型,阐述了流动损失的形成机理。研究表明:向心透平叶轮内部涡系与轴流式透平存在较大差别,且流动分离及涡系主要集中在吸力面侧;设计工况下向心透平叶轮内的主要旋涡包括马蹄涡、通道涡及泄漏涡,其主要表现为通道涡与泄漏涡相互影响和掺混,是主要损失的形成原因;非设计工况下,主流在叶轮叶片前缘处发生大范围的分离及回流,造成了较大的能量损失,但二次流损失所占比例较小。
The three-dimensional viscous numerical simulation of the complex flow inside the impeller was carried out in a cascade environment. Based on the topological theory, the evolution of the flow separation and the development of various vortices in the design conditions and non-design conditions were analyzed , The vortex model in the impeller of the radial heart was initially established and the formation mechanism of the flow loss was expounded. The results show that there is a great difference between the inner vortex system and the axial turbine in the radial turbine impeller, and the flow separation and the vortex system are mainly concentrated on the suction side. In the design condition, the main vortex in the impeller is Horseshoe Vortex, channel vortex and leaking vortex, which are mainly caused by the interaction and mixing of channel vortex and leakage vortex, which are the main causes of formation loss. Under non-design conditions, the mainstream is separated and recirculated in a wide range at the leading edge of impeller blades , Resulting in greater energy loss, but the proportion of secondary loss is smaller.