The prism is white prefabricated concrete with a fluted base able to introduce horizontal light.
棱柱体是白色预制的混凝土，下面一个凹槽底座能够引入水平的光线。
2
Experiments were performed in horizontal and vertical conduits with diameter of 50 mm respectively, adopting air and water as flow media and a triangular prism as the vortex-forming body.