Study Of Wave Simulating Technology Based On Fluent And Numerical Simulation Of Horizontal Forces On Vertical Cylinders From Internal Solitary Waves And Its Experimental Verification

Internal solitary wave is a kind of nonlinear wave which generally takes place at pycnocline in the ocean. It has characteristics of long-wavelength and large-amplitude. Giant wave force is generated during its propagation, which is a significant threaten to oceanic structures and submarines. Researches on internal solitary wave and its influence on structures become more and more meaningful with the increasing attention paid on the exploitation of ocean oil and gas.Research methods of internal solitary wave contain theoretical research, experimental research and numerical simulation. This paper establishes a two-dimensional numerical simulation model with Fluent based on CFD to study internal solitary waves and uses the modal to simulate horizontal force on vertical cylinders from internal solitary waves. The simulation results are verified by the experiment conducted in the laboratory.In the second chapter, the paper introduces the internal solitary wave theories of KdV and mKdV. A three-dimensional numerical simulation model of internal wave is established with Fluent. RNG k-epsilon turbulent model is adopted to close naiver-stokes equation. Velocity entrance method is adopted to make internal solitary wave. VOF method is adopted to catch the interfaces of internal solitary waves. Resource term addition method combined with numerical dissipation is adopted on wave absorption. Innovation of this chapter is using UDF improve velocity entrance of the model based on KdV and mKdV, which achieves the accurate control of the size of internal solitary wave.In the third chapter, the experiment of internal solitary wave conducted in the laboratory is introduced, including experimental methods, equipment, conditions and results. Then compare wave heights, wavelengths, waveforms, flow fields and wave induced velocities between numerical simulation and experiment. Results show that numerical simulation matches the experiment well. The accuracy of numerical simulation is verified. It is an innovation to verify numerical simulation with a same size experiment.In the fourth chapter, a numerical model studying horizontal forces on vertical cylinders from internal solitary waves is established based on the numerical flume in the third chapter. The experiment studying horizontal forces on vertical cylinders from internal solitary waves is introduced, including the size and arrangement of the six cylinders, test equipment and methods. Then compare the results between numerical simulation and the experiment. Results show that numerical simulation matches the experiment well, the feasibility and accuracy of numerical simulation about horizontal forces on vertical cylinders from internal solitary waves is verified by the comparison. Innovation point in this chapter is that cylinders are arranged in different depths, which provides a way to study the distribution of horizontal forces on vertical cylinders from internal solitary waves. It is meaningful to the research on the response of structures from internal solitary waves.Results show that it is an efficient way by using CFD numerical simulation to research horizontal forces on vertical cylinders from internal solitary waves. This method can be adopted into the further research of internal solitary wave. The vertical distribution of horizontal velocity is closed to KdV and mKdV. Horizontal forces on vertical cylinders have a visible difference along with the vertical distribution of cylinders. Cylinder in the upper layer gets the largest force. Cylinder in the range of wave surface gets a small force, and there is no significant shear on this cylinder.