Design, analysis and predicting hydrokinetic performance of a horizontal marine current axial turbine by consideration of turbine installation depth

Abstract

In the last decade, there has been a growth of interest in tidal power as a renewable and clean source of energy. Southern part of Iran is a well placed in this regard, as the currents in this area are primarily tidal. Horizontal Axis Marine Current Turbine (HAMCT) is widely used as an extraction devise for tidal energy. In this paper, Blade Element Momentum Theory (BEMT) and CFD have been conducted on this devise. Based on installation depth of HAMCT, turbine is subjected to gravity wave induced loads. A numerical study was conducted to design, analysis and predict hydrokinetic performance of HAMCT with and without extreme gravity waves. The fluid model has been created with appropriate dimensions. In order to model the high amplitude of wave ocean wave, linear wave theory for gravity waves is used. Numerical results of steady and transient solution have been compared to available experimental data. The simulation results demonstrate that by increasing the installation depth of HAMCT from the free surface, shaft loads and power coefficient of the turbine experience oscillate respectively. The simulation results demonstrate that compared with turbine only rotating in constant inflow, pressure and velocity contours experience oscillation respectively.The results of this study can provide data to choose appropriate installation depth for HAMCT to obtain higher power coefficient and avoid undesirable phenomena e.g. fatigue and cavitation.