Effect of Motion Domain and Velocity on Calculation of Underwater Vehicle Coefficients

Hydrodynamic coefficients have primary importance in determining the maneuvering characteristic of a marine vehicle. The use of computational fluid dynamics (CFD) methods due to the lower cost of these methods compared to laboratory methods in determination of hydrodynamic coefficients have always been considered. Validation of the CFD methods and enhancing their accuracy are the major topics in the application of CFD for the underwater vehicle. The hydrodynamic coefficients of an elliptical-shape underwater vehicle and the effect of motion amplitude and velocity parameters have been investigated by the STAR-CCM+ software and through dynamic overset meshing. The results of the simulations have been compared and analyzed and the error reduction criteria have been presented considering the amplitude dimensions and velocity values in the simulation. In addition, an innovative method for simultaneous calculation of hydrodynamic coefficients of surge motion has been presented which shows good accuracy by comparing the results with theoretical and laboratory data.