Design and optimization of a hydrokinetic turbine duct with CFD

Duct is a special mechanism used to control to flow through turbines. Studies on ducts emerged at the beginning of the 20th century and they were focused on wind turbines. Though hydrokinetic technology is now starting to gain its place in the market, only few attempts have been made to implement duct in their designs. Most of the efforts done on studying ducts follow the traditional method of trial and error which is very time consuming and may lack in accuracy. In the present study new attempt has been made to optimize the output power of an hydrokinetic turbine using a duct mechanism. Though works on duct optimization are available, this study takes an unusual approach in the field of hydrokinetics. Adjoint method combined with mesh morphing tools present in some CFD software were used to optimize an airfoil based cross section duct. All simulations and optimizations have been conducted using ANSYS FLUENT software. At the end of the study, a 40% increase in power output was observed when the hydrokinetic turbine was put inside the designed duct. This result matched closely to the result from theoretical calculations. Key Words: CFD, Hydrokinetic Turbine, Ducted Turbine, Adjoint Method, FLUENT