Investigation of the effect of the water velocity on 8-blades undershot waterwheel performance by computational method

The undershot waterwheel is an old technology recommended as a power plant in rural or remote areas because of its simple construction, technology, and manufacturing ease. Although it has been developed, the effect of water velocity on the undershot waterwheel is still a matter of debate. Therefore, this study investigated the effect of water velocity on the undershot waterwheel’s energy conversion process and hydraulic behaviour by the computational fluid dynamics (CFD) method. Since this study is a follow-up, an 8-blade undershot waterwheel is used for this case. Based on analysis of variance, the water velocity affects the undershot waterwheel performance with categorised negative impact, increasing the water velocity significantly decreasing performance. Allegedly, improving the undershot waterwheel performance by expanding the hydrodynamics force using increasing cross-section areas is recommended. In addition, expanding the cross-section areas of the water stream has an impact on increasing momentum change. Furthermore, the undershot waterwheel is categorised as a reaction turbine because it identified two conversion energy processes that occurred: momentum change and hydrodynamic force.