在拖拽系统水动力理论研究的基础上,根据集中质量法建立曳纲的三维动力学数学模型,将曳纲在空间上离散为一系列节点,同时忽略曳纲的扭转、抖动等,计入张力、重力、浮力和流体阻力的作用,建立曳纲的动态运动数学模型,并通过四阶龙格库塔...在拖拽系统水动力理论研究的基础上,根据集中质量法建立曳纲的三维动力学数学模型,将曳纲在空间上离散为一系列节点,同时忽略曳纲的扭转、抖动等,计入张力、重力、浮力和流体阻力的作用,建立曳纲的动态运动数学模型,并通过四阶龙格库塔方法积分求解,得到曳纲的位置和速度信息,最后利用三维图形引擎OSG(Open Scene Graph)实现拖曳系统的三维可视化。数值计算结果与相关试验数据比较表明,曳纲模型的求解方法是可靠的,同时又保证了仿真的实时性。展开更多
Three-stranded rope is widely used in fishing gear and mooring system. Results of numerical simulation are presented for flow around a three-stranded rope in uniform flow. The simulation was carried out to study the h...Three-stranded rope is widely used in fishing gear and mooring system. Results of numerical simulation are presented for flow around a three-stranded rope in uniform flow. The simulation was carried out to study the hydrodynamic characteristics of pressure and velocity fields of steady incompressible laminar and turbulent wakes behind a three-stranded rope. A three-cylinder configuration and single circular cylinder configuration are used to model the three-stranded rope in the two-dimensional simulation. The governing equations, Navier-Stokes equations, are solved by using two-dimensional finite volume method. The turbulence flow is simulated using Standard κ-ε model and Shear-Stress Transport κ-ω(SST) model. The drag of the three-cylinder model and single cylinder model is calculated for different Reynolds numbers by using control volume analysis method. The pressure coefficient is also calculated for the turbulent model and laminar model based on the control surface method. From the comparison of the drag coefficient and the pressure of the single cylinder and three-cylinder models, it is found that the drag coefficients of the three-cylinder model are generally 1.3–1.5 times those of the single circular cylinder for different Reynolds numbers. Comparing the numerical results with water tank test data, the results of the three-cylinder model are closer to the experiment results than the single cylinder model results.展开更多
文摘在拖拽系统水动力理论研究的基础上,根据集中质量法建立曳纲的三维动力学数学模型,将曳纲在空间上离散为一系列节点,同时忽略曳纲的扭转、抖动等,计入张力、重力、浮力和流体阻力的作用,建立曳纲的动态运动数学模型,并通过四阶龙格库塔方法积分求解,得到曳纲的位置和速度信息,最后利用三维图形引擎OSG(Open Scene Graph)实现拖曳系统的三维可视化。数值计算结果与相关试验数据比较表明,曳纲模型的求解方法是可靠的,同时又保证了仿真的实时性。
基金supported by the National Natural Science Foundation of China (31072246, 30972256)Special Fund for Research on high efficient techniques for Antarctic Krill (20150256)+1 种基金Agro-Scientific Research in the Public Interest (201203018, 201303050-02)the Fundamental Research Funds for Chinese Academy of Fishery Sciences (CAFS) (2012A1301)
文摘Three-stranded rope is widely used in fishing gear and mooring system. Results of numerical simulation are presented for flow around a three-stranded rope in uniform flow. The simulation was carried out to study the hydrodynamic characteristics of pressure and velocity fields of steady incompressible laminar and turbulent wakes behind a three-stranded rope. A three-cylinder configuration and single circular cylinder configuration are used to model the three-stranded rope in the two-dimensional simulation. The governing equations, Navier-Stokes equations, are solved by using two-dimensional finite volume method. The turbulence flow is simulated using Standard κ-ε model and Shear-Stress Transport κ-ω(SST) model. The drag of the three-cylinder model and single cylinder model is calculated for different Reynolds numbers by using control volume analysis method. The pressure coefficient is also calculated for the turbulent model and laminar model based on the control surface method. From the comparison of the drag coefficient and the pressure of the single cylinder and three-cylinder models, it is found that the drag coefficients of the three-cylinder model are generally 1.3–1.5 times those of the single circular cylinder for different Reynolds numbers. Comparing the numerical results with water tank test data, the results of the three-cylinder model are closer to the experiment results than the single cylinder model results.
