Extensional Properties of a Dilute Polymer Solution Following Preshear in Microgravity
Extensional Properties of a Dilute Polymer Solution Following Preshear in Microgravity
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微重力预剪切后稀聚合物溶液的拉伸性能
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
E. M. Fincke
中科院分区：
文献类型：
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作者：
Johannes M. Soulages;G. McKinley;N. Hall;Kevin Magee;G. Chamitoff;E. M. Fincke
剪切历史拉伸流变学实验(Shere)是国际空间站(ISS)的一项实验，旨在研究预切变历史对单轴拉伸流动中稀释聚合物溶液的瞬时拉伸粘度的影响。由于没有万有引力，我们可以在不使液桥下垂的情况下，测量伸展变形停止后流体细丝的毛细变薄。了解聚合物溶液在包含剪切和拉伸运动学的复杂流动中的变形和稀化，在包括纤维纺丝、注塑、食品和消费品加工以及未来的“无容器加工”操作在内的各种行业中尤其重要。Shere实验提供了在施加单轴拉伸流动之前预先剪切测试样品的能力，以探索这种预先剪切对样品拉伸粘度和弹性毛细管变薄的影响。在谢尔主要硬件发射到国际空间站航天飞机任务STS-120后，先后在航天飞机任务STS123和STS-126上发射了两批20和25个流体样本。谢利实验是由宇航员格雷格·查米托夫和迈克·芬克在2008年7月至2009年1月期间进行的。在这次演讲中，我们将重点介绍针对一种具有良好特性的稀溶液所获得的主要结果，并将它们与地面实验进行比较。此外，我们还将展示当前微重力实验结果的潜在应用。
The Shear History Extensional Rheology Experiment (SHERE) is an International Space Station (ISS) experiment designed to study the effects of a preshear history on the transient extensional viscosity of a dilute polymer solution in a uniaxial stretching flow. The absence of gravitational body forces allows us to measure the capillary thinning of the fluid filament after cessation of the extensional deformation without sagging of the liquid bridge. Understanding the deformation and thinning of polymeric solutions in complex flows containing both shearing and extensional kinematics is particularly relevant in a wide variety of industries, including fiber-spinning, injection molding, food and consumer product processing, as well as future “containerless processing” operations. The SHERE experiment offers the ability to preshear the test samples before imposing a uniaxial stretching flow in order to explore the impact of this preshearing on the sample extensional viscosity and elastocapillary thinning. After the SHERE main hardware was launched to the ISS on-board Shuttle Mission STS-120, two batches of 20 and 25 fluid samples were successively launched on-board Shuttle Missions STS123 and STS-126. The SHERE experiments were performed by astronauts Greg Chamitoff and Mike Fincke between July 2008 and January 2009. In this talk, we will focus on the main results obtained for a well-characterized dilute polymer solution and compare them to ground-based experiments. In addition, we will show potential applications of the current microgravity experimental findings.