Optimization of flow-focusing devices for homogeneous extensional flow.
Optimization of flow-focusing devices for homogeneous extensional flow.
复制标题
均匀拉伸流的流聚焦装置的优化。
DOI：
10.1063/1.5037472
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发表时间：
2018
期刊：
影响因子：
3.2
通讯作者：
M. A. Alves
中科院分区：
文献类型：
--
作者：
F. Pimenta;R. G. Sousa;M. A. Alves
我们提出了一种方法的形状优化的流动聚焦装置的目的是创建一个广泛的区域均匀的拉伸流，其特征在于均匀的应变率沿沿着的中心线的设备。所采用的数值例程包括优化器、有限体积求解器和网格生成器，网格生成器对具有由贝塞尔曲线参数化的壁的几何形状进行操作。对具有不同几何特性（通道纵横比和长度）的器件进行了优化。优化的设备的性能进行评估，为不同的雷诺数，流之间的速度比，和流体流变学。布朗动力学模拟也被用来评估λ-DNA分子在器件中的拉伸和弛豫。总体而言，优化的流动聚焦装置在微流体中通常发现的条件范围内产生均匀的延伸流动。在高Weissenberg数下，λ-DNA分子在优化的流动聚焦装置中的延伸接近于在具有等效Hencky应变的理想平面延伸流动中获得的延伸。在这项研究中提出的设备可以是有用的，在微流体应用中利用均匀的拉伸流动和易于控制的Hencky应变和应变速率。
We present a methodology for the shape optimization of flow-focusing devices with the purpose of creating a wide region of homogeneous extensional flow, characterized by a uniform strain-rate along the centerline of the devices. The numerical routines employed include an optimizer, a finite-volume solver, and a mesh generator operating on geometries with the walls parameterized by Bézier curves. The optimizations are carried out for devices with different geometric characteristics (channel aspect ratio and length). The performance of the optimized devices is assessed for varying Reynolds numbers, velocity ratio between streams, and fluid rheology. Brownian dynamics simulations are also performed to evaluate the stretching and relaxation of λ-DNA molecules in the devices. Overall, the optimized flow-focusing devices generate a homogeneous extensional flow over a range of conditions typically found in microfluidics. At high Weissenberg numbers, the extension of λ-DNA molecules in the optimized flow-focusing devices is close to that obtained in an ideal planar extensional flow with an equivalent Hencky strain. The devices presented in this study can be useful in microfluidic applications taking advantage of homogeneous extensional flows and easy control of the Hencky strain and strain-rate.
影响因子：
56.9
作者：
Perkins, TT;Smith, DE;Chu, S
通讯作者：
Chu, S
影响因子：
3.4
作者：
Guillou, Lionel;Dahl, Joanna B.;Kumar, Sanjay
通讯作者：
Kumar, Sanjay
影响因子：
2.3
作者：
Haward, Simon J.;Odell, Jeffrey A.;Yuan, Xue-Feng
通讯作者：
Yuan, Xue-Feng