Cross-flow turbine’s CFD analysis for hydropower generation

The rising demand for affordable and efficient small-scale hydropower systems has driven renewed interest in Cross-Flow Hydro Turbines (CFHTs), particularly for rural and off-grid applications. CFHTs are recognized for their simple design, ease of maintenance, and low installation costs, making them well-suited for low-head sites. Despite limitations related to low head and discharge, they offer moderate efficiency and operational adaptability. This study presents an optimization-based investigation into CFHT performance by varying three key parameters: the number of blades (18 to 22), runner rotational speed (500, 600, and 700 RPM), and inlet blade angle (fixed at 10°), with a constant nozzle entrance arc of 65°. Unsteady computational fluid dynamics (CFD) simulations were conducted to analyze flow behavior and total pressure distribution, from which efficiency and other performance indicators were derived. The results show that the highest efficiency of 99.75% was achieved using 20 blades, a rotational speed of 600 RPM, and an inlet blade angle of 10°. These findings highlight the importance of blade count and operating speed in performance enhancement. This work offers practical insights for improving CFHT design, contributing to the development of efficient, small-scale hydropower solutions for low-head environments.