Design and Analysis of Bio-Inspired Nacelle for Current Energy Turbin

The world's oceans contain a substantial amount of energy, stored in ocean currents and waves. Ocean current energy can be extracted using similar principles to existing wind energy platforms. A problem with such extraction methods is that the velocity of the fluid in ocean currents is too low for efficient energy generation. A potential solution to this problem is the use of a concentrator or diffuser to increase fluid velocity to the blades, but this carries with it extra costs. A more cost effective solution to this problem is presented by the use of a down flow current turbine in which the body geometry can be changed to increase velocity across the turbine blades. A scale of a commercial down flow turbine is tested in a wind tunnel in order to validate CFD simulations. A biologically inspired nacelle based on the Box fish (Ostracion cubicus) is presented and CFD simulations performed using the validated model. It is shown that by changing the body geometry of this down flow turbine, the velocity incident on the turbine blades can be increased for a given free stream velocity and such a design can cost less than a commercially available turbine.