This article presents a numerical study of the forces induced by hydrodynamic impact, that is, the impact of a part of the bottom of the hull on the water surface. The prediction of these efforts is often based on num...This article presents a numerical study of the forces induced by hydrodynamic impact, that is, the impact of a part of the bottom of the hull on the water surface. The prediction of these efforts is often based on numerical simulations to determine the shock intensity of a structure on the surface of a weakly compressible fluid (for example, water). The short duration of the impact is also investigated in this work. This phenomenon occurs especially when a ship encounters a harsh and difficult sea conditions. Under such conditions, it is important to know how to predict the hydrodynamic forces applied to the structure to correctly optimize the ship elements during its design stage or to prevent possible damage. Indeed, various factors such as speed of the ship and height of the swell can cause the hull to partially emerge and then fall violently onto the water surface, which is referred to by naval personnel as tossing or slamming causing vibrations, stresses, and fatigue to the structural elements of the ship. In this work, we present an example of phenomenon modeling and then a numerical study of the different geometries (dihedron) that play a role in different sections of the bow. Then, we compare our present results with the theoretical and experimental results of other researchers in the field. The average interval impact time for a dihedral model corresponding to the section of the chosen ship and other experimental and theoretical data is in good agreement with the experimental and theoretical measurements.展开更多
Recently, offshore renewable energy has received significant attentions from most oceanic countries. Its multiple disciplinary nature appears as a hot research spot. Among those resources, offshore wind has been exper...Recently, offshore renewable energy has received significant attentions from most oceanic countries. Its multiple disciplinary nature appears as a hot research spot. Among those resources, offshore wind has been experiencing a rapid growth with strong industrial and governmental support. Among the research topics related to offshore wind turbine, those related to efficiency and safety issue receive most attentions, and they cover hydrodynamics, aerodynamics, structural dynamics, elasticity and so on. Hydrodynamics is considered as the key of these research for offshore wind turbine. This is not only because it is the fundamental of ocean engineering, but also it is similar to low speed aerodynamics which is the key of wind turbine rotor. In order to provide a comprehensive understanding of the important problems of offshore wind turbine hydrodynamics, we briefly review the evolution of offshore wind turbine and discuss the hydrodynamics problem associated with the research and development activities.展开更多
文摘This article presents a numerical study of the forces induced by hydrodynamic impact, that is, the impact of a part of the bottom of the hull on the water surface. The prediction of these efforts is often based on numerical simulations to determine the shock intensity of a structure on the surface of a weakly compressible fluid (for example, water). The short duration of the impact is also investigated in this work. This phenomenon occurs especially when a ship encounters a harsh and difficult sea conditions. Under such conditions, it is important to know how to predict the hydrodynamic forces applied to the structure to correctly optimize the ship elements during its design stage or to prevent possible damage. Indeed, various factors such as speed of the ship and height of the swell can cause the hull to partially emerge and then fall violently onto the water surface, which is referred to by naval personnel as tossing or slamming causing vibrations, stresses, and fatigue to the structural elements of the ship. In this work, we present an example of phenomenon modeling and then a numerical study of the different geometries (dihedron) that play a role in different sections of the bow. Then, we compare our present results with the theoretical and experimental results of other researchers in the field. The average interval impact time for a dihedral model corresponding to the section of the chosen ship and other experimental and theoretical data is in good agreement with the experimental and theoretical measurements.
基金supported by the Ministry of Science and Technology of China(Grant No.2017YFE0132000)the National Natural Science Foundation of China(Grant No.11872248)supported by the Science and Technology on Underwater Test and Control Laboratory Foundation(Grant No.61424070603).
文摘Recently, offshore renewable energy has received significant attentions from most oceanic countries. Its multiple disciplinary nature appears as a hot research spot. Among those resources, offshore wind has been experiencing a rapid growth with strong industrial and governmental support. Among the research topics related to offshore wind turbine, those related to efficiency and safety issue receive most attentions, and they cover hydrodynamics, aerodynamics, structural dynamics, elasticity and so on. Hydrodynamics is considered as the key of these research for offshore wind turbine. This is not only because it is the fundamental of ocean engineering, but also it is similar to low speed aerodynamics which is the key of wind turbine rotor. In order to provide a comprehensive understanding of the important problems of offshore wind turbine hydrodynamics, we briefly review the evolution of offshore wind turbine and discuss the hydrodynamics problem associated with the research and development activities.
