Calculation of Additional Turbulent Force by Slicing Method for Underwater Unpowered Vehicle under Layered Ocean Current

Conventional additional turbulent force calculation method based on constant ocean current velocity introduces large error in the trajectory calculation of an underwater unpowered vehicle due to complexity of ocean current, which influences the vehicle attitude of water outlet. This paper calculates the additional turbulent forces of the vehicle by using the slicing method based on the non-dimensional hydrodynamic coefficient obtained with CFD method, and compares the forces with the ones from conventional method under even ocean current and layered ocean current. Conclusions are drawn that the results obtained with both conventional and slicing methods are consistent with each other under even ocean current, while the slicing method can achieve more accurate result under layered ocean current by selecting proper slicing number.