Numerical Simulation of Wake Flow Field in Pitch Motion of Underwater Vehicle

Abstract

The frequent pitching motion of underwater vehicle during the mission will produce a more complex hydrodynamic wake, which is important for the detection and tracking of underwater vehicles. In this paper, a numerical method is presented to simulate the wake field during the pitching motion of an underwater vehicle by combining the dynamic overset grid method. The evolution law of the wake field is analyzed based on the DARPA SUBOFF simplified model. The effects of underwater vehicle speed on the velocity and turbulent kinetic energy of the wake field and the effects of the longitudinal inclination of the underwater vehicle on the extent of the wake field are discussed.It is found that the wake velocity is positively correlated with the sailing speed of the underwater vehicle, the turbulent kinetic energy of the wake field is directly proportional to the 1.75 power of the sailing speed of the underwater vehicle, and the range of wake field is positively correlated with the pitch angle of underwater vehicle. The larger the pitch angle is, the larger the intensity and size of vortex formed in the flow field are, and the farther the vortex can propagate to the rear of underwater vehicle wake.