Research on the Energy Harvesting Coefficient and Near Wake Flow of a Dual Vertical Axis Wave Current Coupled Power Generation System

This article takes the outline of the sailfish as an airfoil profile and establishes a dual vertical axis water turbine model. The centrifugal and axial flow water turbines share a common drive shaft, which is connected to the generator. The centrifugal water turbine utilizes tidal energy, while the axial flow water turbine utilizes wave potential energy. Based on Fluent UDF and sliding grid, numerical simulation of hydraulic turbines was conducted, and it was found that the centrifugal turbine had the highest energy harvesting coefficient at an attack angle of 25 °, while the axial flow turbine had the highest energy harvesting coefficient at an attack angle of 35 °. The centrifugal turbine has the highest energy gain when the tip speed ratio is 1.25 and the Reynolds number is 1.3e ^ 5. The axial flow turbine has the highest energy gain when the tip speed ratio is 1.5 and the Reynolds number is 5.5e ^ 4. The downstream turbine impeller utilizes the Kantar effect to perform work, but the boundary layer separation is severe and vortex shedding is obvious, which seriously affects the energy harvesting efficiency of the turbine.