Performance Assessment of an Underwater Glider with Independently Controllable Main Wings by CFD Analysis

摘要

The purpose of this study is to establish a method for assessing the performance of an underwater glider with independently controllable main wings and an experimental vehicle named 'ALEX' has been developed as a test-bed for such an underwater glider. Observations in a diving-training pool demonstrate that the ALEX glider has remarkably high performance motion capabilities; e.g., forward and backward going, rapid turning, spirally diving/surfacing, stopping in place, and propulsion by oscillating hydrofoils. ALEX also has the capacity of cruising with a much smaller gliding angle as compared with conventional fixed-wing underwater gliders. However, it is not easy to obtain the hydrodynamic forces under various conditions by experimentation. In this research work, computational fluid dynamics (CFD) analysis was applied to estimate the hydrodynamic forces acting on ALEX. The relationship between the gliding angle, angle of attack and angle of incidence of the main wings at a certain gliding velocity were obtained. It was, thus, verified that CFd analysis can be a useful tool to estimate the hydrodynamic forces acting on the glider. The analysis data are also useful in establishing a mathematical model for simulating the motions and manoeuvring of the ALEX glider.