Vol.:(0123456789) 1 3 Iranian Journal of Science and Technology, Transactions A: Science https://doi.org/10.1007/s40995-019-00685-6 RESEARCH PAPER Simulation of Tidal Energy Extraction by Using FLUENT Model F. Hosseinibalam 1  · S. Hassanzadeh 1  · M. Mirmohammadi 1 Received: 5 May 2018 / Accepted: 25 January 2019 © Shiraz University 2019 Abstract Numerical simulation of tidal current energy extraction has raised the knowledge about the issue of energy extraction from marine sources. A water channel in laboratory scale is simulated using FLUENT code. FLUENT is a state-of-the-art com- puter software for CFD analysis based on the fnite volume method, and its applications have been over almost the entire fuid dynamic spectrum. FLUENT has been used for tidal energy extraction simulation in this study. A disk, which gener- ates a pressure drop due to energy loss, drives the tidal stream turbine in the model. The fuid model, which can be freely deformed, has been used for the free water surface. Numerical results show that a wake is formed in the back of the tidal fow turbine and an accelerated fow around, especially below the energy generator device is created. It is supposed that the drop of the water surface due to the energy extraction in the model has an important efect on improving the wake of the turbine. Keywords Turbulent trail · Porous media · VOF 1 Introduction Today, because of the world’s energy crisis and the fnitude of fossil fuels, access to new sources of energy is of utmost importance. Therefore, in the peak of the crisis, only coun- tries which have already conducted studies on new energies will be able to overcome the situation. Marine or ocean energy is one of the renewable types of energy that have been considered along with other sources such as solar or wind power. Waves and tidal energy are inspected as the most important subset of marine energy. Tidal energy is a probed energy source that is related to the gravitational pull of the moon and the sun. Being less costly and resulting in very low pollution are the most important benefts of using tidal energy (Boyle 1996). Even though the initial costs of constructing power production systems for tidal energy are remarkably high, the energy extracted from tidal current is more useful than that of power plants such as fossil fuel (Bryden 2006; Frau 1993). Numerical simulation has been widely used to develop technology standards for different applications such as wind turbines (Pope et al. 2010), energy extraction from tidal currents (Sun et al. 2008) and wave energy conversion systems (El Marjani et al. 2008). In this study, a water channel at laboratory scale is simu- lated using FLUENT code. Tidal energy extraction to a disk drive is modeled by using porous media that lead to changes in kinetic energy of the water along the disk. MacLeod et al. (2002), Bryden and Couch (2006) supposed that the free surface does not change. They concluded that this assump- tion has no efect on the fow feld, but it is not true when the efects of tidal farmland are considered. In this study, the volume of fuid (VOF) method is used in the modeling of free surfaces. In computational fuid dynamics, the volume of fuid (VOF) method is a free-surface modeling technique, i.e., a numerical technique for tracking and locating the free surface (or fuid–fuid interface). It belongs to the class of Eulerian methods which are characterized by a mesh that is either stationary or moving in a certain prescribed man- ner to accommodate the evolving shape of the interface. As such, VOF is an advection scheme—a numerical recipe that allows the programmer to track the shape and position of the interface—but it is not a standalone fow solving algorithm. The Navier–Stokes equations describing the motion of the fow have to be solved separately. There are many interesting sites for tidal energy develop- ment in Iran, having a 1770 km southern coastline, along * F. Hosseinibalam fhb@phys.ui.ac.ir 1 Physics Department, Faculty of Sciences, University of Isfahan, 81746 Isfahan, Iran