| With the progress of science and technology and the needs of production and life,human exploration of the universe has gradually deepened,so the launch frequency of rockets and satellites is also increasing.In order to get rid of the disadvantages of traditional land-based rocket launch,the majority of scholars and related research institutions began to study the launch of offshore rocket satellites with greater safety and flexibility.As the main carrier of offshore rocket launch,the offshore platform will be affected by different degrees of wind,wave,current and their coupling under the condition of marine environment,resulting in complex flow phenomena such as large motion amplitude and wave,which will affect the normal operation of rocket launch.In addition,when the rocket is launched,the offshore platform will be subjected to huge impact loads,which will affect the stability of the platform and the launch attitude of the rocket.In order to improve the performance of the offshore satellite launch platform,the liquid tank structure is arranged in the platform column,and a liquid tank with damping plate is proposed.Based on the CFD numerical simulation software,the sloshing effect in the liquid tank is analyzed when the damping plate is arranged in different types and positions.The hydrodynamic performance of the offshore rocket launch platform with damping plate is numerically studied.The main contents are as follows:(1)According to the main research contents of this thesis,the research status of tank sloshing,offshore satellite launch,semi-submersible offshore platform motion performance and numerical wave tank are summarized.(2)Based on the content of numerical calculation in this thesis,based on CFD viscous flow theory,the theoretical basis of this thesis and the free surface tracking and dynamic overlapping grid technology used in this thesis are introduced.(3)A single vertical column liquid tank model was established.For the cylindrical liquid tank partially filled with liquid,the numerical simulation value of the liquid sloshing natural frequency of the model was compared with the theoretical value to verify its accuracy.Secondly,the liquid sloshing in the tank with and without damping plates is compared,and the influence of different types and different positions of damping plates on the sloshing of the tank in the cylinder is analyzed.(4)A high-quality three-dimensional numerical wave-making tank was established.The basic wave conditions required for calculation in this thesis were simulated by using the velocity inlet boundary wave-making method.The convergence analysis of grid size and time step for wave height and period in the numerical tank was carried out.The accuracy of the numerical wave-making method in this thesis was verified by comparing the wave acquisition data with the theoretical value.At the same time,based on the numerical tank established in this thesis,the accuracy of single column climbing under viscous flow numerical analysis is verified,which provides the basis and support for the subsequent calculation of wave climbing of the platform.Finally,based on the numerical method in this thesis,a four-column liquid tank semi-submersible platform is established to study the motion response and wave climbing of liquid tanks with and without damping plates under different wave periods,liquid filling rates and wave heights.(5)In order to simulate the thrust generated by the launch of the offshore rocket launch platform,this thesis uses the custom function method in STAR-CCM+ software to simulate the unsteady force of the offshore rocket launch,and studies the influence of the rocket launch position on the platform motion response.Finally,based on the unsteady force simulation method and the optimal launch position of the rocket under the condition of rocket launch operation,the motion response of the offshore satellite launch platform with or without liquid tank and the liquid level change near the column are numerically simulated. |
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