تجزیه و تحلیل عملکرد از یک توربین کنونی HAT و ویژگی های جزر و مدی جریان دنباله

Having very strong current on the west coast with up to 10 m tidal range, there are many suitable sites for the application of tidal current power (TCP) in Korea. The turbine, which initially converts the tidal energy, is an important component because it affects the efficiency of the entire system. To design a turbine that can extract the maximum power on the site, the depth and duration of current velocity with respect to direction should be considered. To extract a significant quantity of power, a tidal current farm with a multi-arrangement is necessary in the ocean. The interactions between devices contribute significantly to the total power capacity. Thus, the study of wake propagation is necessary to understand the evolution of the wake behind a turbine. This paper introduces configuration design of horizontal axis tidal current turbine based on the blade element theory, and evaluating its performance with CFD. The maximum efficiency of the designed turbine was calculated as 40% at a tip speed ratio (TSR) of 5. The target capacity of 300 kW was generated at the design velocity, and the performance was stable over a wide range of rotating speeds. To investigate the wakes behind the turbine, unsteady simulation was carried out. The wake velocity distribution was obtained, and velocity deficit was calculated. A large and rapid recovery was observed from 2D to 8D downstream, followed by a much slower recovery beyond. The velocity was recovered up to 86% at 18D downstream.

Ocean energy, including tidal current power (TCP) among numerous alternative energy sources, has the greatest potential for use throughout the world. The kinetic energy available within a tidal current can be converted into rotational power by a turbine; therefore, turbine design and performance verification is important in developing TCP systems. Many studies have been performed on tidal turbine design based on the blade element momentum theory (Batten et al. [1], Baltazar and de Campos [2]). Bahaj et al. [3] conducted an experimental demonstration of tidal turbine performance. Jo et al. [4] compared the performance of three different types of turbines by experiment. Jo et al. [5] investigated the interference effects of multi-arrayed turbines. Faudot and Dahlhaug [6] introduced a performance analysis for tidal turbines under the effects of regular waves. In this study, a horizontal axis turbine (HAT) was designed based on the blade element theory and validated using computational fluid dynamics (CFD). Performance of the turbine was verified by experiment in a circulating water channel (CWC) and compared with the CFD results.

The TCP system is a promising energy source with great potential since it is predictable and continuous regardless of weather conditions and seasons. HAT blade design involves the sequencing and arranging of specific foils with appropriate twist angles and chord lengths; its procedures and methods are presented in this paper. A performance analysis of the turbine is important and was verified by CFD. The reliability of the blade design could be estimated using CFD by presenting the streamlines and pressure fields around the blade. The performance and torque curves were determined and the turbine characteristics were analyzed. The interactions between devices contribute significantly to the total power capacity. Thus, interaction problems need to be investigated for generating maximum power in a specific field. The study of wake propagation is necessary to understand the evolution of the wake behind a turbine.