Numerical investigation of load characteristics by internal solitary wave on submarines in fluids with continuous density change

Internal solitary waves (ISW) often appear in the actual ocean and carry huge energy. In order to study the interaction between the ISW and the underwater objects, considering the variation law of the fluid density along the depth direction in the actual ocean, the numerical calculation model for the ISW and the submarine in the stratified fluid is established based on the Korteweg de Vres (KdV) theory and the RANS method. The load characteristics of the ISW on the submarine are studied by using the overset mesh technology and the VOF method. When the submarine passes through the ISW, the change of its buoyancy will cause a sharp change in the vertical load. The ISW-induced flow field will also affect the force on the submarine. The ISW-induced forces increase with the increase of the ISW amplitudes. When the submarine is completely below the peak of the waveform, the load is mainly affected by the flow field structure; the force amplitude is small, and the impact of the submergence depth is small.