Numerical prototyping of co-axial droplet generators

HARISPE, DAVID; CARAM, JORGE P.; URTEAGA, RAÚL; KLER, PABLO A.

Congreso; III Brazil-Argentine Microfluidics Congress - VI Congreso de Microfluídica Argentina; 2022

High performance numerical simulations allows the development of numerical prototypes thatfacilitate the process of designing and optimizing devices for microdroplet generation throughdifferent virtual experiments. The formation of microdroplets from one fluid (dispersed phase) intoanother (continuous phase) can occur in a controlled manner in a discontinuous flow (“dripping”), ora continuous jet (“jetting”) which eventually breaks into droplets far downstream in an uncontrolledmanner. Although experimental systems that are able to produce droplets of up to three phaseshave been reported, the transition from dripping to jetting regime is not yet fully understoodeven for simple two-phase (co-flow) systems. Moreover, the operating conditions needed formicrodroplets to be experimentally produced in two-phase systems are still under study. Thevalidation with experimental coaxial generators in the dripping regime, will allows the evolution ofthe numerical prototype to a more complex version involving three phases, planar chips, and thetransport of reactive substances for synthesis simulation. For the computational model, basiliskan Open Source software for solving fluid flow equations based on the volume-of-fluid method, isused. The results obtained in the computational study of a coaxial system in the dripping regime,for a two-phase model are presented and compared with experiments present in the literature.