Dynamics model is essential and critical for the successful design of navigation and control system of an underwater vehicle. In this paper, the equation of motion of the ROV was estimated by using numerical methods. And this was done
by using many software have been used such as SOLIDWORKS, ANSYS FLUENT, ANSYS CFX and COMSOL MULTIPHYSICS.
The equation of motion in 6 DOF consists of mass and inertia parameters found by SOLIDWORKS. Damping parameters
including linear and quadratic damping estimated using steady state simulation in ANSYS FLUENT. Another component in the equation of motion is the added mass parameter and this can be estimated by applying free undamped oscillation of ROV in water with a spring using Fluid structure interaction in COMSOL MULTIPHYSICS software. The results show that the CFD can provide the hydrodynamic property for the ROV as well. The thrust configuration matrix can be also estimated by measuring the distances from the thrusters to the center of gravity.