An Analysis on Hydrodynamic Coefficients of Torpedo Bodies and The Corresponding Measurement Scenarios

Study of the hydrodynamic characteristics of an underwater body requires a good knowledge about hydrodynamic coefficients of the body. The fluid forces acting on an underwater body and their effects on the flow field are depended to the body geometry, motion speed, body maneuvering, the fluid properties and the flow regimes on body surfaces. Thereafter knowing the hydrodynamic coefficients, one can predicts the body motions in Six degree of freedoms (6 DOF) by considering the vehicle as a rigid body and using of the second Newton’s law. At this paper, in order to determine more important coefficients affecting the vehicle motion and its stability, all of the hydrodynamic coefficients for conventional torpedo bodies are analyzed. Then the corresponding experimental scenarios for measuring the important coefficients are discussed in details. These analyses show that only twelve coefficients are more important and necessary for hydrodynamic studies of these bodies. It must be noted that the emphasis of this paper is not on the numerical solution of these hydrodynamic equations.