Viscoelastic behaviour of fluids in micro-fluidic applications

这个博士项目将涉及微封闭环境中粘弹性流体的流变学和流体动力学行为的研究和表征。该项目的很大一部分将是考虑微型设备的高效性能问题，如增强混合或增强传热。为了绕过小尺度问题所特有的低雷诺数的限制，通过在工作流体中加入柔性的、高分子量的聚合物来消除低回流中线性的基本条件。在这些条件下，紊流的典型的混沌运动是由流体的弹性引起的（弹性湍流）。第二组相关活动将关注更普遍的问题，即生物流体在体内或微流体设备（如芯片实验室）中的流变特性。该活动将主要通过数值模拟进行，使用高精度的方法，如光谱或光谱元素方法。所采用的技术将特别具有挑战性，因为它们需要在复杂的几何形状中重现复杂的流变行为。还计划由伙伴研究小组进行实验验证。

This PhD project will involve the study and characterization of the rheological, and fluid, dynamic behaviour of viscoelastic fluids in micro-encloses. A large part of the project will be to consider the problem of efficient performance in micro-devices like enhanced mixing or enhanced heat transfer. In order to bypass the limitation of the low Reynolds number which characterizes small scale problems, the basic condition of linearity in low Re Flows is removed by adding flexible, high molecular weight polymers to the working fluid. In these conditions the chaotic motions, typical of turbulent flows, are caused by the elasticity in the fluid (elastic turbulence). A second group of related activities will regard the more general problem of rheological characterization of biological fluids both in vivo or in micro-fluidics devices such as lab-on-chip. The activity will mainly be conducted by numerical simulation using highly accurate methods such as spectral or spectral elements methods. The techniques employed will be particularly challenging since they will require the possibility to reproduce complex rheological behaviours in complex geometries. Experimental validations conducted by partner research groups are also planned.