Optimization Methodology Of Small Scale Horizontal Axis Shrouded Tidal Current Turbine

An investigation of the performance of a small-scale horizontal axis shrouded tidal current turbine was carried out numerically and experimentally. Blade Element Momentum (BEM) theory is used to find out the optimum parameters of the rotor blades such as chord length, and twist angle distribution. Since the power output is proportional to the third order of incoming velocity, so, even a slight increase of the fluid velocity will produce a notable increment of the power output. Thus, a shrouded duct equipped with a ring-type flange has used to enhance the turbine performance. The paper aims to find out the optimum diffuser configuration to minimize the duct size and reduce the structural loads. A surface response method of the ANSYS-Workbench has used to optimize four design parameters including the curvature of the diffuser, flange height, inlet, and outlet length. All calculations were carried out using a commercial software ANSYS-CFX17.2. Results showed that the optimum parameters of the shrouded turbine could produce a high power output with a rate of increase up to 25 % as compared with a conventional turbine. An experiment of a small-scale tidal current turbine was performed. A comparison between CFD results and experimental data has done. The experimental results showed a good agreement with those from CFD analysis.