Friction Loss Analysis of Air Gap Fluid in Rim-Driven Generator

The air gap of the rim-driven generator for tidal current energy is intentionally designed to remain open, facilitating unimpeded seawater flow within the gap. The magnitude of fluid friction losses in the air gap is decided by the variation in the flow state of seawater, which is influenced by rotor agitation. The accurate determination of the generator’s output properties relies heavily on precise calculation of fluid frictional losses in the air gap. The objective of this study is to simulate the hydrodynamics of seawater flow in an air gap and analyze the impact of different air gap structures on the flow field of the generator. The fluid friction losses are then determined based on the results of the simulation analysis, serving as a foundation for an accurate calculation of the working performance.