Numerical and Analytical Calculation of Munk Moment in Real Flow for an Autonomous Submarine in Pure Sway Motion in PMM Test

The Munk moment may make the vessel unstable in simultaneous Surge and Sway motions. In this paper the munk moment was calculated by computational fluid dynamics (CFD) and finite volume method (FVM) for an autonomous submarine. Furthermore the added mass coefficients were calculated for computation of munk moment using analytical formulation in potential flow. The damping coefficients were also calculated. The unstedy state numerical simulation of real flow for surge and sway motions has been performed. The turbulent effects were considered by using k-ω sst turbulence model. Using Planar Motion Mechanism (PMM) in pure sway situation, the forces and moments were calculated. The overset mesh was used for grid generation in computational domain. The mesh independency has been also prerformed. Using sixth order polynomial interpolation for forces and moments of numerical simulation, the hydrodynamic coefficients were calculated. The results showed good agreement with experimental data. Finally, the munk moment of numerical simulation and analytical formulation have been compared. Furthormore N_v ̇ was calculated based on potential theory and also compared with numerical and experimental ones.