Development of an Innovative Divertor Cooling Method Utilizing Self-forming Flow Field in Multi-elbow Piping

本研究通过流动显示实验，详细分析了多弯头管道布局下游的旋流流动特性，选择了可能适合偏滤器冷却的管道布局，以替代旋流管诱导的流场。首先，采用两个弯头三维连接的双弯头布置，估计弯头曲率半径的影响。结果表明，曲率半径越小，旋流越强。随后，测试了包括三个短弯头的五个三弯头布局，其中第一和第二弯头以及第二和第三弯头分别三维连接的3D-3D布局给出了最强的涡流。另一方面，湍流能量等湍流统计数据在双肘布局中变得最大。这些布局将在下一步从传热方面进行测试。

In this study, characteristics of swirling flows induced downstream of multi-elbow piping layouts were minutely analyzed by means of flow visualization experiments, and potentially suitable piping layouts were selected for divertor cooling as an alternative to the flow field induced by a swirl tube. First, the influence of curvature radius of the elbow was estimated by using a dual-elbow layout in which two elbows were connected three-dimensionally. And it was found that the shorter the curvature radius was, the stronger the swirling flow became. Subsequently, five three-elbow layouts comprising three short elbows were tested, and a 3D-3D layout, in which the first and second elbows and the second and third elbows were connected three-dimensionally, respectively, gave the most strong swirling flow. On the other hand, turbulent statistics such as turbulent energy became largest in the dual elbow layout. These layout will be tested in terms of heat transfer in the next step.