Abstract Hybrid vertical axis turbines that combine Savonius and Darrieus turbines on a single shaft have been proposed as a way of combining the excellent starting torque of Savonius turbine with the high operational efficiency of the Darrieus turbine. Although hybrid turbines with improved starting characteristics have been demonstrated in literature, the performance of these turbines at higher tip speed ratios have been poor. In this work systematic study of stand-alone Savonius and Darrieus turbines have been carried out using experimental and numerical techniques as a precursor to studying their roles in hybrid configuration. The radius ratio of the two turbines, when combined in the form of a hybrid turbine, is identified as an important parameter that dictates the performance of hybrid turbines. An expression for an optimal radius ratio is derived and a methodology for designing hybrid turbines is proposed. The efficiency in energy conversion by hybrid turbine can be expressed in terms of a parameter called effectiveness given by the ratio of power produced by the hybrid turbine to the sum of the power produced by individual Darrieus and Savonius turbines. This idea has been verified through experiments and numerical simulations.

中文翻译：

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混合涡轮机设计方法以更好地提取风能

摘要 将Savonius 和Darrieus 涡轮机组合在一个轴上的混合垂直轴涡轮机已被提出，作为将Savonius 涡轮机的出色启动扭矩与Darrieus 涡轮机的高运行效率相结合的方式。尽管文献中已经证明了具有改进启动特性的混合涡轮机，但这些涡轮机在较高叶尖速比下的性能一直很差。在这项工作中，使用实验和数值技术作为研究它们在混合配置中的作用的先驱，对独立的萨沃尼厄斯和大流士涡轮机进行了系统研究。两个涡轮机的半径比，当以混合涡轮机的形式组合时，被认为是决定混合涡轮机性能的重要参数。导出了最佳半径比的表达式，并提出了设计混合涡轮机的方法。混合涡轮机的能量转换效率可以用称为效率的参数表示，该参数由混合涡轮机产生的功率与单个 Darrieus 和 Savonius 涡轮机产生的功率之和的比率给出。这个想法已经通过实验和数值模拟得到了验证。