Comprehensive Review of Sediment Erosion Mechanisms and Their Impact on Francis Turbines

Abstract Sediment erosion significantly affects hydraulic machinery, particularly Francis turbines operating in sediment-laden flows. This phenomenon plays a crucial role in reducing the energy output and operational challenges. Given that, Francis turbines play a vital part in the context of hydropower generation and are the most widely used among hydro turbines, they must withstand significant effects from sediment erosion. Identifying and mitigating erosion in these types of turbines is an important endeavor. To address this issue, several experimental and numerical investigations have been conducted to predict erosion rates based on the sediment and flow properties. This study examines the impact of sediment erosion using existing knowledge associated with mechanisms of sediment erosion, focusing on the Francis turbine. The present work gathered and analyzed data to enhance our understanding of sediment behavior, wear mechanisms concerning sediment properties, flow parameters, and target material response. Furthermore, it indicated that sediment properties and fluid velocity are proportional to erosion rate on the Francis turbine components, and a sediment size lower 0.2 mm is significant for hydraulic design of the turbine parts to mitigate the erosion effect. Overall, this review sheds light on the relationships between various erosion factors.