The application of computational fluid dynamics for autonomous underwater vehicle hydrodynamic coefficients

Computational Fluid Dynamics (CFD) has progressed rapidly in the past fifty years. It has been used in many industrial fields such as air and space and marine engineering. With the use of CFD, the simulation of fluid behavior would be possible while allocating less cost and time. CFD is used on the basis of Reynolds Averaged Navier–Stokes (RANS) equations for the calculation of hydrodynamic coefficients which are needed in the maneuverability study of underwater vehicles (UWV). These coefficients are used in the investigation of underwater vehicles maneuverability. The computations are performed for three geometrical shapes representing typical AUVs presently in use. The simulation of the resistance tests up to 20 degrees of yaw angle was conducted for an Autonomous underwater vehicles with different length-to-diameter ratios. The results were compared with the experimental data and current quasi-experimental relationships. These comparisons suggested that the predictions of CFD were adequately precise and accurate. These predictions indicated that there was a non-linear relationship between forces and moments, and the lateral speed. Moreover, non-linear hydrodynamic coefficients were calculated in addition to linear ones.