Hydrodynamics Modeling of Control Fins of TL-AUV by Computational Fluid Dynamics Analysis

The hydrodynamics of a control fin for an autonomous underwater vehicle (AUV) is modeled based on computational fluid dynamics analysis (CFD). The fin is designed with a low aspect ratio and working in front of the propulsor. CFD tests consist of control fin in uniform flow and fully appended vehicle. The test of control fin in uniform inflow examines the lift characteristics of the low aspect ratio fin. The results confirms that the conventional rudder models underestimate the lift force generation. The influence of tip vortex generation is dominant to reduce the lift-to-drag ratio and delay stall at high angle of attack conditions. The fully-appended vehicle tests consist of fin deflection, drift, and circular motion tests. The effects of the propulsor on fin hydrodynamics is found to be negligible. The inflow modeling by hydrodynamic force measurement is physically interpreted using flow field analysis.