Abstract: This paper investigates the validation of an empirical method that estimates the hydrodynamic coefficients of streamlinedunderwater vehicles. These coefficients are non-dimensional parameter appearing in the equation of motion of the vehicle. Datcom(U.S, Air Force compilation code) is used to determine these coefficients in aquatic medium. The body configuration in this studyincludes axisymmetric body without wing tail or body tail. Results obtained with the Datcom are presented here and compared toexperimental results taken from a Planar Platform Mechanism mounted over a towing tank. A 6dof balance was used to extract themeasurements forces and moments acting on the derived vehicle. These measurements were carried out at typical speeds ofautonomous underwater vehicles (0.2-0.6 m / s) by varying the angles of inclination (0-15 degrees). This study was limited to theaxial forces which mean the coefficient of drag. Static hydrodynamic characteristics computed by Datcom method are shown to agreeclosely with experimental results for torpedo slender body of circular cross sectional.

Keywords: Underwater Vehicle, Hydrodynamic coefficients, Towing Tank, Datcom.