Modeling of Laminar Flow Static Mixers

Nagi Elabbasi, Xiaohu Liu, & Stuart Brown
Veryst Engineering LLC, Needham, MA, USA

Mike Vidal & Matthew Pappalardo
Nordson EFD, East Providence, RI, USA

Veryst Engineering, a company that provides consulting in engineering design and product manufacturing, has collaborated with Nordson EFD, one of the leading manufacturers of precision dispensing systems, to optimize their static mixers.

Static mixers are inexpensive and efficient mechanisms for mixing laminar viscous fluids, where molecular diffusion is minimal. Here, the fluids must be mechanically mixed, and the convective properties of the fluid effectively enhanced. Being able to predict a mixer’s performance leads to more efficient designs, better utilization of materials and improved dispensing quality.

The team used COMSOL Multiphysics to perform a CFD and mass transfer analysis of the overall mixer performance of a static mixer, and to predict the overall flow pattern and pressure drop. Then, using massless particle tracing data, they mapped the path of fluid particles to compare it to experiments that replicated this same data.

The analyses provided a valuable tool for understanding the flow patterns inside the mixer beyond what is possible through experimentation, while the good agreement between model and experiment gave them confidence to further use modeling to improve mixer design.

Comparison between experimental data and numerical mixing predictions at three sections along the first half of the mixer.