Flow Characteristics inside the Duct with Various Diffuser Angles for the Single Point Moored TCP System

Abstract

With many countries implementing carbon dioxide reducing policy recently, the demand of green energy has been increased. Tidal current power, one of the ocean energy resources, has great potential worldwide due to its high energy density. Since the kinetic energy of the flow at the upstream is proportional to the cube of the velocity, the flow speed is the most critical factor for power generation affecting on the performance of the system. A duct system can accelerate the flow velocity, which could expand the applicable area of TCP systems to relatively lower velocity sites. The shapes of the inlet and outlet could affect the flow rate inside the duct. To investigate the performance of the duct, variable ducts were preliminary designed and a series of simulations were carried out using ANSYS-CFX v13.0 CFD software. This study introduces a ducted turbine system that can be moored to a seabed. A performance estimation and comparison of results with conventional tidal converters were summarized in this paper.