A Flow-Visualization Study of a Multiple Hydrofoils Duct with Particle Image Velocimetry Equipment in KIOST

Abstract

Recently, a tidal current turbine has numerous attentions because it generates a sustainable and predictable renewable energy. The tidal current turbine is one of the systems that extract kinetic energy from tidal current, and there are several types of the tidal current turbine depending on its operating motion. However, most turbines have limitations to respond the chaotic current in the ocean. One of the solutions, a duct system, can be actively responsive to different magnitude and direction of the inflow. In this study, we explored the flow velocity controllability of a diffuser-type multiple hydrofoils duct by experimental and numerical flow visualization approaches. The experimental and numerical analysis were compared each other with the same speed at 0.6 m/s. When the diffuser angle is changed from 0 to 7.5 degree, the ratio of increase inside the duct is varied from 1.82 to 2.53. Also, the experimental and numerical analysis shows that the increment ratio is 1.13 and 1.07 in the same condition, respectively. Even though the conditions between the experimental and numerical analysis are somewhat different, the increment ratio inside the duct is similar each other effectively even under. In addition, we introduce the particle image velocimetry (PIV) equipment of the Korea Institute of Ocean Science and Technology (KIOST) water channel facility used in the experimental approaches as well as newly setting-up PIeral types of the tidal current turbine depending on its operating motion. However, most turbines have limitations to respond the chaotic current in the ocean. One of the solutions, a duct system, can be actively responsive to different magnitude and direction of the inflow. In this study, we explored the flow velocity controllability of a diffuser-type multiple hydrofoils duct by experimental and numerical flow visualization approaches. The experimental and numerical analysis were compared each other with the same speed at 0.6 m/s. When the diffuser angle is changed from 0 to 7.5 degree, the ratio of increase inside the duct is varied from 1.82 to 2.53. Also, the experimental and numerical analysis shows that the increment ratio is 1.13 and 1.07 in the same condition, respectively. Even though the conditions between the experimental and numerical analysis are somewhat different, the increment ratio inside the duct is similar each other effectively even under. In addition, we introduce the particle image velocimetry (PIV) equipment of the Korea Institute of Ocean Science and Technology (KIOST) water channel facility used in the experimental approaches as well as newly setting-up PI