Modeling and Stability Analysis of Prototype Mixed Kinematic Bulk, Free Surface, and Interfacial Flows of Viscoelastic Fluids

这是一个赠款，以解决有关的问题，聚合物和聚合物基复合材料已被确定为关键的安全，美国的大多数聚合物和复合材料制造工艺的基本部分涉及流动的聚合物在腔的任意形状与或不加强。 工艺生产量和产品质量通常受到流动不稳定性的限制。 纯弹性不稳定性的存在表明，所有的聚合物加工操作，无论它们多么缓慢，都容易发生不稳定性。 出于这个原因，理解流体弹性对流动和稳定性的代表性的散装，自由表面和界面流的影响是至关重要的。 完全并行化，高阶有限元技术将被用来研究一些原型的二维和三维自由表面和界面流动的粘弹性流体。 具体而言，工作将集中在调查流动修改由于流体弹性在混合剪切/拉伸流，以及研究流体弹性和非平衡能量效应对这类流动的稳定性的作用。 特别感兴趣的是，以确定的机制（S）是负责粘弹性不稳定性的混合运动流，这是经常遇到的聚合物和复合材料的加工。

This is a grant to address problems related to polymeric and polymer matrix composite materials that have been identified as being key to the security of the U.S. The basic part of most polymer and composite materials manufacturing processes involves flow of polymers in cavities of arbitrary shape with or without reinforcement. Process throughput and product quality are often limited by the onset of flow instabilities. The existence of purely elastic instabilities suggest that all polymer processing operations, however slow they may be, are prone to instabilities. For this reason understanding the influence of fluid elasticity on flow and stability of representative bulk, free surface and interfacial flows is crucial. Fully parallelized, higher-order finite element techniques will be used to study a number of prototype two and three-dimensional free surface and interfacial flows of viscoelastic fluids. Specifically, the work will focus on investigating flow modifications due to fluid elasticity in mixed shearing/elongational flows as well as examining the role of fluid elasticity and non-equilibrium energetic effects on stability of this class of flows. Of particular interest is to identify the mechanism(s) that are responsible for viscoelastic instabilities in mixed kinematic flows which are routinely encountered in processing of polymers and composite materials.