Numerical Simulation of the Maneuvering Motion Wake of an Underwater Vehicle in Stratified Fluid

Abstract

When a vehicle moves underwater, disturbance is generated and a wake remains that destroys the original free surface and produces a new wake. In order to study the mechanism and characteristics of the wave-making wake generated by the maneuvering motion of an underwater vehicle in density-stratified fluid, the k-ε model and the VOF method that is based on the RANS equation were used in this paper to analyze the SUBOFF model in stratified fluid at different drift angles. Numerical simulation of the maneuvering motion was carried out under these angles, and the corresponding changes in flow field caused by this motion were analyzed. The results from the comparison and analysis of the surface wave wakes under different drift angles in stratified fluid show that with the increasing drift angle, the motion wake of the vehicle still exhibits obvious Kelvin wave system characteristics. However, there are significant changes in hydrodynamic performance. The asymmetry of the surrounding flow field will increase with the increase in the drift angle. The pressure of the underwater vehicle is inversely proportional to the velocity of the surrounding flow field, and the amplitude of the peak and trough of the free surface wave is linearly related to the change in the drift angle. The numerical simulation can serve as a reference for the non-acoustic detection of the motion heading of an underwater vehicle and the motion trajectory of anti-reconnaissance underwater vehicles under actual sea conditions.

Review on the Hydro- and Thermo-Dynamic Wakes of Underwater Vehicles in Linearly Stratified Fluid

“…Anisotropy of the surface wave crest and trough, along with a larger influencing zone of Kelvin waves, was evident in the stratified case (Figure 3). Shi et al [101] have studied the wave-making wake of maneuvering underwater vehicles in density-stratified fluid using RANS simulation, revealing Kelvin wave system characteristics and notable hydrodynamic performance changes with increasing drift angle. Jones and Paterson [102] have investigated swirl's impact on the near wake of a selfpropelled axisymmetric vehicle with three propulsor schemes, noting reduced potential energy in the CRP configuration.…”

“…Wang et al [103] and Li et al [104] have used CFD and the modified Korteweg-de Vries theory to simulate the interaction between internal solitary waves (ISWs) and submerged bodies, discussing forces and moments on submarine models at different submergence depths [105]. He et al [106] have proposed a new numerical scheme for ISW generation with a current, demonstrating the interaction between Shi et al [101] have studied the wave-making wake of maneuvering underwater vehicles in density-stratified fluid using RANS simulation, revealing Kelvin wave system characteristics and notable hydrodynamic performance changes with increasing drift angle. Jones and Paterson [102] have investigated swirl's impact on the near wake of a selfpropelled axisymmetric vehicle with three propulsor schemes, noting reduced potential energy in the CRP configuration.…”