Simulation Of Submarine Wake Evolution And Flow Field Characteristics

The characteristics of the flow field around the submarine will affect the maneuverability of the submarine.The far field wake of the submarine will affect its stealth performance as a target.Therefore,it is of great significance to study the flow field characteristics of the submarine near and far field.At present,there is a standard SUBOFF submarine model in the world,and a detailed experimental database is established.Therefore,this paper will use CFD to study the wake evolution and flow field characteristics of the fully appended SUBOFF model.Firstly,the RANS is used to calculate the submarine flow field during the straight movement state.The calculation results are compared with the experimental results,and the degree of coincidence is high.The accuracy of the calculation method is verified.Next,this paper study the flow field characteristics of the near field and the wake evolution of the far field when the submarine straight movement speed is different.For the near field,the submarine surface pressure,velocity distribution and vortex core region are mainly analyzed,while the far field is concerned with the evolution of vortex in the wake.The results show that during the straight movement,the high pressure is generated at the bow of the submarine,and the sail and sterns generate tip vortices.The horseshoe vortex is formed at the junction between the sail and hull,and five pairs of vortices appear in the wake region.During the evolution of the wake,the vortex diffuses to the surrounding and the vortex intensity decreases.An increase in the speed of the submarine will result in an increase in the intensity of the vortex in the flow field.Secondly,it studies the flow characteristics of the near field during the maneuvering and the wake evolution of the far field.The different angles are selected to analyze the changes of flow field characteristics in yaw and pitch.the pressure on the windward side of the submarine is higher than that on the leeward side in maneuvering,and the hull generates body vortices due to the flow separation.The vortex intensity generated during the maneuvering in the wake is much higher than the straight movement.In yaw,there are two vortices distributed at up and down of the wake field.In pitch,there are two vortices about bilateral symmetry in the wake field.As the angle increases,the intensity of the vortex in the wake is larger,and the flow distance can be farther.Finally,based on the VOF model,capturing the pattern of the free surface wake when the submarine moves near the free surface.Study the effects of different depths and Fr numbers on surface waves.The larger the Fr number,the larger the wavelength,amplitude,and angle of the surface wave.The increase in latent depth only reduces the amplitude of the surface wave and has no effect on the wavelength and the angle.