ANSYS CFX replaces the towing tank experiments

The hydrodynamic interaction between an Autonomous Underwater Vehicle (AUV) manoeuvring in close proximity of another larger vessel can cause rapid changes in the motion of the AUV which can lead to a collision between the two vessels. Being relatively small and self-piloted, the AUV is more susceptible to interaction effects. In an aim to predict the manoeuvring performance of an AUV under the effects of the interaction, the Australian Maritime College (AMC) has conducted a series of computer simulations and captive model experiments in AMC's towing tank. This research study develops two numerical models to simulate pure sway and pure yaw motions of an AUV at different relative lateral and longitudinal positions to a larger underwater vessel using ANSYS CFX Computational Fluid Dynamics (CFD) software. The variables investigated include the sway and drag forces acting on the SUBOFF which were then used to obtain the hydrodynamic coefficients. In order to establish the credibility of the numerical models, validation with Experimental Fluid Dynamic (EFD) measurements were carried out. The predictions of the numerical models were found to be in good agreement with the experimental measurements.