Abstract

A parametric study on the stability and morphology of the liquid cone in a flow focusing process is carried out through experimental and numerical methods. For the numerical simulations, we solve the Navier-Stokes equations coupled with a diffuse interface method. A scaling analysis which considers the competition between the viscous shear stress and the interfacial tension force is proposed, showing the effect of flow rates, geometrical parameters and liquid physical properties on the cone instability. The experimental and numerical results validate the scaling law and further show the effects of parameters on the cone morphology. We study the flow fields inside the liquid cone, with emphatic focus on the recirculation flow pattern which occurs at relatively high viscosity ratio between the focusing and the focused liquids. The occurrence of recirculation flow is close related to the tangential velocity distribution at both sides of the cone interface, and the change of flow rates and geometrical parameters is found to significantly affect the size of the recirculation flow. This study is expected to give a guidance to the optimization of process parameters in flow focusing system, which would contribute to the formation of a stable cone-jet structure and the production of microdroplets with high throughput.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.