Experimental and numerical study of a vertical axis tidal turbine performance

Abstract

In the present study, a vertical axis tidal turbine with movable blades was investigated using experimental and numerical methods. A laboratory model of this turbine type nominated as Hunter turbine was manufactured and tested in an established test rig. In the next step, 3D steady Reynolds-Averaged Navier-Stokes (RANS) equations were solved by CFD using k- turbulence model to predict turbine's performance. The numerical results were verified by the experimental data. In addition, effects of duct, neighbor turbines distance and layout on the power coefficient were investigated. The results showed that the power coefficient of a turbine in the present of ducts with area ratios of 0.1 to 0.26 increased from 0.14 to 0.29. It was also observed that in a four-turbine farm, the output power is maximum for a distance of 13D (diameter of turbine) between neighbor turbines and area ratio of 0.26. For this case, the farm's performance factor is 0.944.

Novel Design of a Vertical Axis Hydrokinetic Turbine –Straight-Blade Cascaded (VAHT–SBC): Experimental and Numerical Simulation

“…The RANS solver is a coupled flow solver, where the momentum and continuity equation are solved simultaneously. This approach has a low number of iterations and does not required pressure correction to maintain mass conservation, leading to a more robust and accurate solver [26,27]. Design Modeler Software was used to create the VAHT-SBC geometry, which consists of turbine domain, rotational domain and flow domain.…”

“…In another study, a modified vertical axis tidal turbine, called the Hunter turbine, was tested. It was shown that its Cp is about 0.19 [26].…”

Design and performance optimization of a very low head turbine with high pitch angle based on two-dimensional optimization

“…ANSYS CFX is an implicit solver which solves continuity and momentum equations simultaneously. In this way, there is no need for pressure correction term to enforce mass conservation, and as a result, converged solutions are obtained with lesser iterations compared to other methods such as SIMPLE algorithm [29]. Discretization of equations is carried out by implementing element-based finite-volume combined method which uses shape functions to describe related variables.…”

An experimental study of a flow-accelerating hydrokinetic device

“…20 and Derakhshan et al. 21 both used CFD model studies to show how the inclusion of a nozzle/duct improved turbine performance by 78% and 52%, respectively, in comparison to a conventional turbine design but both studies used the smaller turbine area as the reference area. Jin et al.…”