The purpose of shipping risk early-warning is that some effective measures are taken to reduce risk probability before the risk brings heavy loss.The shipping risk has the dynamic characteristic,so the key of early-wa...The purpose of shipping risk early-warning is that some effective measures are taken to reduce risk probability before the risk brings heavy loss.The shipping risk has the dynamic characteristic,so the key of early-warning is to choice risk early-warning index correctly and evaluate risk grade quantitatively.According to the element extension theory,the rhombus inference model is applied to establish the index system.And the problem of risk grade evaluation can be solved by the assessment model of multi-index performance parameter,which is developed by the extension engineering method.Finally,the main shipping risks and their grades are identified by the example analysis based on the statistical data,which shows the effective and feasible of the shipping risk early-warning method.展开更多
Ship floating condition in regular waves is calculated. New equations controlling any ship＇s floating condition are proposed by use of the vector operation. This form is a nonlinear optimization problem which can be ...Ship floating condition in regular waves is calculated. New equations controlling any ship＇s floating condition are proposed by use of the vector operation. This form is a nonlinear optimization problem which can be solved using the penalty function method with constant coefficients. And the solving process is accelerated by dichotomy. During the solving process, the ship＇s displacement and buoyant centre have been calculated by the integration of the ship surface according to the waterline. The ship surface is described using an accumulative chord length theory in order to determine the displacement, the buoyancy center and the waterline. The draught forming the waterline at each station can be found out by calculating the intersection of the ship surface and the wave surface. The results of an example indicate that this method is exact and efficient. It can calculate the ship floating condition in regular waves as well as simplify the calculation and improve the computational efficiency and the precision of results.展开更多
The coupled dynamic responses of two pontoons while connecting with each other in irregular waves are calculated by means of 3D potential flow theory. The computation is used to find the optimal status for connecting ...The coupled dynamic responses of two pontoons while connecting with each other in irregular waves are calculated by means of 3D potential flow theory. The computation is used to find the optimal status for connecting at certain sea state. On the basis of the relative motion of two pontoons in irregular waves,visual FORTRAN programming language,as well as open graphics library (OpenGL),is used to develop a set of virtual reality system,which is fully interactive and with realistic effect. The transfinite interpolation scheme is applied for the mesh generating of the wave surface,and the wave motion is simulated by surface elevation,which is calculated by 3D potential flow theory.展开更多
The dynamic responses of two pontoons while connected with each other in irregular waves are calculated by means of three-dimensional （3-D） potential flow theory. The computation is to find the optimal status for co...The dynamic responses of two pontoons while connected with each other in irregular waves are calculated by means of three-dimensional （3-D） potential flow theory. The computation is to find the optimal status for connection at a certain sea state. On the basis of the relative motion of two pontoons in irregular waves, Visual FORTRAN programming language, as well as OpenGL （Open Graphics Library）, is used to develop a set of virtual reality system of the relative motion of two pontoons, which is fully interactive with realistic effect. The transfinite interpolation scheme is applied for the mesh generation of wave surface, and the wave motion is simulated by surface elevation and calculated by 3-D potential flow theory.展开更多
基金the Natural Science Foundation of Tianjin (No.07JCYBJC13100)
文摘The purpose of shipping risk early-warning is that some effective measures are taken to reduce risk probability before the risk brings heavy loss.The shipping risk has the dynamic characteristic,so the key of early-warning is to choice risk early-warning index correctly and evaluate risk grade quantitatively.According to the element extension theory,the rhombus inference model is applied to establish the index system.And the problem of risk grade evaluation can be solved by the assessment model of multi-index performance parameter,which is developed by the extension engineering method.Finally,the main shipping risks and their grades are identified by the example analysis based on the statistical data,which shows the effective and feasible of the shipping risk early-warning method.
基金financially supported by the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(Grant No.51321065)the Research Fund of State Key Laboratory of Ocean Engineering of Shanghai Jiao Tong University(Grant No.1104)
文摘Ship floating condition in regular waves is calculated. New equations controlling any ship＇s floating condition are proposed by use of the vector operation. This form is a nonlinear optimization problem which can be solved using the penalty function method with constant coefficients. And the solving process is accelerated by dichotomy. During the solving process, the ship＇s displacement and buoyant centre have been calculated by the integration of the ship surface according to the waterline. The ship surface is described using an accumulative chord length theory in order to determine the displacement, the buoyancy center and the waterline. The draught forming the waterline at each station can be found out by calculating the intersection of the ship surface and the wave surface. The results of an example indicate that this method is exact and efficient. It can calculate the ship floating condition in regular waves as well as simplify the calculation and improve the computational efficiency and the precision of results.
基金the Natural Science Foundation of Tianjin of China(No.07JCYBJC13100)
文摘The coupled dynamic responses of two pontoons while connecting with each other in irregular waves are calculated by means of 3D potential flow theory. The computation is used to find the optimal status for connecting at certain sea state. On the basis of the relative motion of two pontoons in irregular waves,visual FORTRAN programming language,as well as open graphics library (OpenGL),is used to develop a set of virtual reality system,which is fully interactive and with realistic effect. The transfinite interpolation scheme is applied for the mesh generating of the wave surface,and the wave motion is simulated by surface elevation,which is calculated by 3D potential flow theory.
基金supported by the National Natural Science Foundation of China(Grant No.50579047)
文摘The dynamic responses of two pontoons while connected with each other in irregular waves are calculated by means of three-dimensional （3-D） potential flow theory. The computation is to find the optimal status for connection at a certain sea state. On the basis of the relative motion of two pontoons in irregular waves, Visual FORTRAN programming language, as well as OpenGL （Open Graphics Library）, is used to develop a set of virtual reality system of the relative motion of two pontoons, which is fully interactive with realistic effect. The transfinite interpolation scheme is applied for the mesh generation of wave surface, and the wave motion is simulated by surface elevation and calculated by 3-D potential flow theory.
