A new CFD method for determination of translational added mass coefficients of an underwater vehicle

In this paper, a new computational fluid dynamics approach is suggested to calculate translational longitudinal and transverse added mass coefficients of an underwater vehicle. In this method, the linear accelerated motion of the underwater vehicle is numerically simulated based on unsteady Reynolds Averaged Navier-Stokes equations using ANSYS CFX software. Velocity and acceleration related forces are extracted from the simulation results, from which the added mass coefficients are extracted. To validate obtained results, initially, the drag and added mass coefficients of an ellipsoid are calculated using the present method and compared with the available corresponding analytical and experimental results. Moreover, an acceleration sensitivity study was performed, indicating that calculated added mass coefficients were acceleration independent. The obtained results from the suggested numerical method agreed well with those obtained from the analytical and experimental methods, indicating that the present CFD method can be used to obtain the added mass coefficients of more complicated geometries, including the underwater vehicle used in this study. The proposed CFD method is not complicated and time-consuming. It can be used as a reliable and inexpensive method to extract translational added mass coefficients of underwater vehicles instead of expensive experimental methods or other CFD methods simulating oscillatory motions.