Viscoelastic behaviour of fluids in microfluidic applications

这个PHD项目将包括研究和表征微囊中粘弹性流体的流变学和流体动力学行为。该项目的很大一部分内容将是考虑强化混合或强化传热等微型设备的高效性能问题。为了绕过表征小规模问题的低雷诺数的限制，通过在工质中加入柔性的高分子聚合物，消除了低再流动中线性的基本条件。在这些条件下，湍流的典型混沌运动是由流体中的弹性(弹性湍流)引起的。第二组相关活动将涉及体内或芯片实验室等微流体设备中生物流体的流变学特征这一更普遍的问题。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，因为它们将要求有可能在复杂的几何形状中重现复杂的流变行为。由伙伴研究小组进行的实验验证也在计划中。

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.