带分流叶片向心涡轮内部流场分析

Investigation of a Radial-Flow Turbine with Splitter-blade

为了详细研究某型向心涡轮的流动特性和内部流场结构,采用准三维与全三维数值模拟方法对其内部流场进行研究,分别得到多个转速下的特性曲线与主要参数分布,对两种数值模拟方法得到的特性线进行对比,并对设计点的全三维数值模拟得到的流场进行分析。计算结果表明,准三维与全三维数值模拟计算得到的特性线基本相同,计算特性线时可以采用准三维方法,减少计算时间。通过对全三维数值模拟的流场特征的分析,初步了解了向心涡轮内部的流动规律,在设计点叶片前缘和尾缘附近有不同程度的气流损失存在,为进一步改进该向心涡轮设计有一定的参考价值。

A three - dimensional flow field of a small radial - flow turbine has been investigated by two methods of numerical simulation in this paper. The characteristic curves and primary parameters of different rotation speeds have been obtained. Through comparison and analysis, the result shows that the characteristic curves calculated by the quasi -three -dimensional method and by the three- dimensional method are basically the same. The characteristic curve can be obtained by using the quasi - three - dimensional method which needs shorter time than by using the three - dimensional method. By analyzing the characteristics of the flow field of the three dimensional numerical simulation, the initiative knowledge of the flow rule inside the radial - flow turbine is obtained, which shows that the flow losses exist, in different degrees, nearby the leading edge and the trailing edge of the blade at the design point. The numerical simulation can be used in the improvement and redesign of the turbine.