Optimization of flow-focusing devices for homogeneous extensional flow

• Type: Article in International Scientific Journal
• Date: 2018

Authors

Pimenta, F (Author) Other; Sousa, RG (Author) Other; Alves, MA (Author) FEUP

Journal

Title: Biomicrofluidics

Vol. 12

ISSN: 1932-1058

Publisher: American Institute of Physics

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-00P-NV6

DOI: 10.1063/1.5037472

Abstract (EN): 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 Bezier 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 lambda-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 lambda-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 strainrate. Published by AIP Publishing.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 24