Flow Analysis of Tidal Turbine Array Interaction Using LES

Abstract

Geographical location of Malaysia is endowed with natural resources such as coal and fossil fuels. Unfortunately, these natural resources will run out shortly if the Malaysian government does not take appropriate measures to conserve them. To ensure that the area has enough energy and sources, a system of utilizing and introducing renewable energy such as solar, rainwater, wave and tidal current energy is established. Vertical axis tidal turbine (VATT) for shallow water applications is the main topic of this study where computational fluid dynamics (CFD) via Large-eddy simulation (LES) and Reynolds-averaged Navier-Stokes (RANS) simulation was performed in investigating the influence of the array interaction of tidal turbines. The VATT is the most suitable tidal turbine in Malaysia because the depth of the water in Malaysia ranges between 20m and 30m. In addition, the hypothetical actuator disk as a representation of the tidal turbine devices, with different turbulence models for simulating tidal turbine wakes interaction was performed. The tested turbulence models include the k-epsilon, Large Eddy Simulation (LES) and Smagorinsky-Lilly. The evaluation was done by comparing the wake generation between LES and RANS simulations’ results against the set of published experimental data regarding various arrays for the tidal turbines. The discussion involves three main parts: (i) pre-processing which concentrates on creating the model and setup parameters, (ii) processing which concentrates on visualizing the simulation data and lastly (iii) post-processing which concentrates on defining the results obtained from the ANSYS software.