Numerical Investigation on Erosion Characteristics of Archimedes Spiral Hydrokinetic Turbine

The Archimedes spiral hydrokinetic turbine (ASHT), an innovative horizontal-axis design, holds significant potential for harvesting energy from localized ocean and river currents. However, prolonged operation can result in blade erosion, which reduces efficiency and may lead to operational failures. To ensure reliability and prevent damage, it is essential to accurately identify the locations and progression of wear caused by sand particle impacts. Using a CFD–DPM approach, this study systematically investigates the effects of sand concentration and particle size on erosion rates and distribution across nine ASHT configurations, along with the underlying physical mechanisms. The results indicate that erosion rate increases linearly with sand concentration due to higher particle impact frequency. Erosion zones expand from the blade tip edges toward mid-span regions and areas near the hub as concentration increases. Regarding particle size, the erosion rate increases rapidly and almost linearly for diameters below 0.6 mm, but this growth slows for larger particles due to a “momentum–quantity trade-off” effect. Blade angle also exerts a tiered influence on erosion, following the pattern medium angles > small angles > large angles. Medium angles enhance the synergy between normal and tangential impact components, maximizing erosion. Erosion primarily initiates at the blade tips and edges, with the most severe wear concentrated in these high-impact zones. The derived erosion patterns provide valuable guidance for predicting erosion, optimizing ASHT blade design, and developing effective anti-erosion strategies.