Design and development of an autonomous underwater vehicle

Abstract

This thesis presents the computation of both steady and unsteady hydrodynamic derivatives required for the design and control of an Autonomous Underwater Vehicle (AUV). The unsteady hydrodynamic derivatives were determined by calculating the added mass force acting on the AUV using the Ansys AQWA software. The results obtained for the AUV was validated by simulating a sphere model and comparing the results with the analytical values. The steady hydrodynamic derivatives were obtained by conducting Computational Fluid Dynamic (CFD) simulations. The k-ω SST model was used to predict the drag force acting on the AUV during surge, heave and sway motions. The realizable k-ε turbulence model was used to predict the moments acting on the AUV during roll, pitch and yaw motions. Enhanced wall treatment and overset mesh interface was used during the rotational simulations. Therefore, the full added mass matrix and hydrodynamic damping matrix of the Fossen model was obtained.