On fluid-body and fluid-network interactions
On fluid-body and fluid-network interactions
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关于流体-体和流体-网络相互作用
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Samire Balta
中科院分区：
文献类型：
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作者：
Samire Balta
本论文提出了动态耦合流体体和流体网络相互作用的研究。目的是开发数学模型并解决有关固体与周围流体以及固体与固体和分支网络中流动之间相互作用的某些问题。考虑交互的三种一般配置。首先，研究通道中被流体包围的刚体。其次，检查流动中刚体的升力。第三，研究具有多个分支和重连接的流体动力学网络。关于第一种配置，主要关注的是当主体穿过时随时间变化的压痕的影响，以及容纳壁的柔性补片的影响。分析检查的早期反应表明，墙壁变形的影响逐渐增大。还研究了随后的物体与通道壁的有限时间碰撞以及该物体后面的不稳定非线性尾流的特性。在第二种配置中，我们研究了薄固体从表面升空的标准以及随之而来的不稳定二维运动。物体可以在有限的时间内升空并飞走或返回表面。找到了飞走的临界值。关于第三种配置，研究了借助外部端部压力对内部流动网络的控制以及各个容器形状和长度的影响。合理推导了单一的非线性演化方程，该方程在一定范围内接受所有端部压力以及容器形状整体特征的影响，决定了整个网络的流量。
The thesis presents a study of dynamically coupled fluid-body and fluid-network interactions. The aim is to develop mathematical models and address certain problems regarding the interaction between solid and surrounding fluid as well as solid and solid and flow in branching networks. Three general configurations of the interaction are considered. First, a rigid body surrounded by a fluid in a channel is studied. Second, lift-off of a rigid body in flow is examined. Third, fluid dynamical networks with multiple branching and reconnections are investigated. Regarding the first configuration, the prime concerns are with the effects of a time dependent indentation, as the body travels through, and with the effects of a flexible patch of containing wall. Early-time responses examined analytically show the gradually growing influence from the distortion of the walls. Ensuing finite-time clashing of the body with the channel walls and the properties of the unsteady nonlinear wake behind this body are also investigated. In the second configuration, we investigate criteria for lift-off of a thin solid body from the surface and the ensuing unsteady two-dimensional motion. The body can either lift off and fly away or return to the surface in a finite time. A critical value for fly-away is found. In reference to the third configuration, control of the internal flow networks by virtue of the outer end pressures is investigated together with effects from the individual vessel shapes and lengths. A single nonlinear evolution equation is derived rationally which within a certain range admits the influence of all the end pressures as well as the overall features of vessel shape and determines the flow through the whole network.