(363j) Modelling of Fluid Flow and Mass Transfer in a Multi-Channel Microfluidic Reactor Using Computational Fluid Dynamics.

In flow visualization experiments studies in micro channels, we require information on the fluid flowrates, heat transfer coefficients (in case of reaction), mass transfer coefficients, size and stability of droplets etc. These data are useful for designing microfluidic processes, scaling up, fine tuning process parameters and, optimization. The microfluidic dimension is really small - surface tension, capillary and viscous effects become more prevalent compared to inertia forces and there are increased interactions between phases and species dissolved in them. Some cons in conducting experimental observations are the time it takes to design and set-up. Also, several experiments are conducted to vary so many parameters and the workflow is often involved. The research is focused on modelling and simulating a parallel multiple-channel microfluidic reactor using Computational Fluid Dynamics techniques. These channels are comprised of thousands of micron-sized steel fibers that bring into contact two immiscible phase with enhanced mixing and separation capabilities. Two-phase fluid flow in a T-junction pipe has been modelled using the COMSOL software and the droplet break-up was observed. In addition, the velocity, pressure and fluid-fluid interphase plots are presented. When fibers are added, large difference in the scales of features are present in the reactor model become evident. This had an effect on computing power. The models had to be solved using high performance computing. The simplification of the model by the application of symmetry and periodic boundary conditions was also explored. The results of these modifications are also reported. The interface is an important parameter in optimizing the mass transfer. Results from parametric studies on relative viscosity and contact angle ratio on the droplet size and interfacial area of droplet are also presented.