Moving Mesh as Transient Approach for Pico Scale Undershot Waterwheel

Abstract

The computational fluid dynamics (CFD) method is often used for undershot waterwheel (USWW) studies. The CFD method is a suitable solution for investigating physical flow phenomena on USWW so that its energy conversion process can be appropriately understood. The transient simulation is necessary to study the flow of physical phenomena. However, there is no recommendation for the transient approach for USWW. The boundary conditions for the transient approach often used for rotating case objects is a moving mesh. Therefore, this study investigates moving mesh as a USSW transient approach to predict its performance. Based on the results, the average deviation from simulation results to experimental data of torque is 22.1%, mechanical power is 5.75%, and efficiency is 5.75%. The average deviation reading of torque is 2.93 N·m (not a significant difference), mechanical power is 0.47 W, and efficiency is 1.19%. Further, the curve data simulation results to experimental data show a similar pattern, expressed by exponential for torque and polynomial for mechanical power and efficiency. Thus, a transient approach using the moving mesh feature is recommended for the USWW case; because the data pattern and reading deviation are reasonable.