A Numerical Method of Flow through a Cross-Flow Runner

The internal flow in a cross-flow turbine is very complicated because the water passes through only a part of the runner. Therefore this type of turbine has been designed and manufactured until now on the basis of Banki's one-dimensional analysis and empirical results. In this report, the flow inside a cross-flow runner is analyzed two dimensionally. The unsteady flow along streamlines in the relative system of the runner is calculated numerically and the flow along the runner periphery is investigated. Additionally, calculated results are compared with experimental data and good agreement between them is demonstrated. Furthermore, it is made clear that the flow inside the runner is exceedingly nonuniform along the runner periphery.