Modelling and analysis on the effect of wrap-around inlet channel to vortex flow for micro hydro application

The Gravitational Water Vortex Turbine is a new and underdeveloped micro hydro system. Thus, this field still not fully explored and many design and parameters need to study. It brings the efficiency of the vortex turbine still very low which is below than 40%. There are a lot of factors that able to influence the efficiency of vortex turbine performance such as the design of basin and inlet configuration of basin. This study is focused on Computational Fluid Dynamics (CFD) analysis of water vortex formation and hydrodynamic flow characteristic. For more specific, this study focusses to compare and analyse the vortex formation and its hydrodynamic characteristic with respect to the performance. There are two different configurations were developed which are no wrap-around inlet and wrap-around inlet. Aside that, three models of wrap-around inlet with radius curvature of 0.27 m, 0.28 m and 0.30 m were developed for the optimization purpose. These models were designed using Solidwork and simulated using Ansys CFX. The experimental work also done for validation purpose. The percentage difference between the experimental and simulation is 7.94%, which is modest enough to demonstrate that the simulation setting usable. In the result, it is focused on the water streamline, vortex profile, water velocity and optimization. Based on the findings, the wrap-around inlet computed higher and symmetric vortex formation, unform and high magnitude of velocity and the streamline also distributed well compared to no-wrap around inlet model. While for the optimize model, wrap-around with 0.27 m radius of curvature was the most efficient among the tested models. With the same reasons, it can create a high velocity with symmetrical vortex