Akademik Məlumat İdarəetmə Sistemi
AIAA Aviation 2019 Forum, Texas, United States Of America, 17 - 21 June 2019, pp.1-9, (Full Text)
This paper focuses on feasibility and assessment of extracting energy from water stream existing in Golden Gate Strait. Optimal design of hydrofoil is carried out for hydrokinetic turbines to improve their hydrodynamic performance in Golden Gate Strait with the low-speed current. Particle Swarm Optimization (PSO) method is applied and coupled with XFoil. A B-spline curve is used to parameterize the hydrofoil shape. The coordinate’s values of the control points are designated to act as optimization parameters. Five hydrofoils from root to tip are designed for a turbine at low current speed with three blades. Hydrofoils are optimized from hub to tip in distances 0.4, 1.2, 2.4, 3.4, and 4.4 m. Harp_Opt which is based on Blade Element Momentum theory is used to obtain the optimum chord length and twist angle distribution along the blade, and these values are applied to initialize optimization and solving procedure. Finally, power coefficient, rotational speed, cavitation criteria, and power are calculated for optimized turbine and compared to the first turbine and Betz criteria. At the tip of the blade, the summation of cavitation number and minimum pressure coefficient is estimated to be 1.8 that is far from zero, so the probability of cavitation occurrence is very low. Power coefficient is computed using Harp_opt for both initial turbines with hydrofoil NACA 4415 and turbine with optimized cross sections from hub to tip. Power coefficient is improved 26 percent for speeds 0.5 to 2 m/s and 50 percent for speeds 2 to 3 m/s.