排序方式: 共有21条查询结果,搜索用时 31 毫秒
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深海观测系统脐带缆形态分析及计算 总被引:3,自引:0,他引:3
通过对水下拖曳系统脐带缆索的受力情况、形态进行分析,建立了三维空间缆索的物理模型和数学模型,并在此基础上编制了计算程序,对6000m深海观测系统脐带缆的性状进行了模拟计算,其结果为深拖系统最佳缆长的确定提供了理论依据。 相似文献
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Flexible segment model (FSM) is adopted for the dynamics calculation of marine cable being laid. In FSM, the cable is divided into a number of flexible segments, and nonlinear governing equations are listed according to the moment equilibriums of the segments. Linearization iteration scheme is employed to obtain the numerical solution for the governing equations. For the cable being laid, the payout rate is calculated from the velocities of all segments. The numerical results are shown of the dynamic motion and tension of marine cables being laid during velocity change of the mother vessels. 相似文献
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氮气浮标是一种新型的剖面浮标,通过增加蓄能器作为被动浮力调节模块,可以利用海洋压差实现更有效率的剖面运动。由于蓄能器的加入,氮气浮标的运动特性相对于常规浮标有所变化。基于一款深海剖面浮标,利用理论分析和运动仿真的方法研究了氮气浮标的运动特性,对氮气浮标主动体积改变量与剖面运动深度之间的对应关系、氮气浮标的剖面运动形式以及氮气浮标的定深悬浮稳定性进行研究。研究表明,氮气浮标只需要主动对浮标体积做较小的改变即可完成同等深度的剖面运动,节省了浮标完成一次剖面运动的能量消耗。但蓄能器的引入增加了浮标完成剖面运动需要的时间,且给浮标的运动带来了突变性和不稳定性。 相似文献
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拖缆动力学离散化计算的后处理方法研究 总被引:2,自引:0,他引:2
拖缆的计算一般都是将拖缆离散化,建立非线性的动力学平衡方程组,通过龙格库塔法、Newton-Raphson迭代法等方法对非线性方程组进行求解.本方法是先将拖缆离散成若干段,列出离散段节点处的水动力学方程,并进一步建立节点处关于角加速度的线性平衡方程组,通过对角加速度的求解计算来解决拖揽的动力学问题.在计算过程中,将拖揽节点处关于角度的非线性问题转化为角加速度的线性问题,简化了求解非线性方程组的计算过程,避免了非线性方程组迭代求解中的初始点问题. 相似文献
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本文在文献[1]的基础上,对三维空间水下缆索的张力、性状等问题进行了初步的探讨,给出了作为初值问题的水下缆索张力、性状等求解方法,从而为进一步研究水下缆索提供了一定的理论基础。 相似文献
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The dynamic calculations of slender marine risers, such as Finite Element Method (FEM) or Modal Expansion Solution Method (MESM), are mainly for the slender structures with their both ends hinged to the surface and bottom. However, for the re-entry operation, risers held by vessels are in vertical free hanging state, so the displacement and velocity of lower joint would not be zero. For the model of free hanging flexible marine risers, the paper proposed a Finite Difference Approximation (FDA) method for its dynamic calculation. The riser is divided into a reasonable number of rigid discrete segments. And the dynamic model is established based on simple Euler-Bernoulli Beam Theory concerning tension, shear forces and bending moments at each node along the cylindrical structures, which is extendible for different boundary conditions. The governing equations with specific boundary conditions for riser’s free hanging state are simplified by Keller-box method and solved with Newton iteration algorithm for a stable dynamic solution. The calculation starts when the riser is vertical and still in calm water, and its behavior is obtained along time responding to the lateral forward motion at the top. The dynamic behavior in response to the lateral parametric excitation at the top is also proposed and discussed in this paper. 相似文献