Lattice Boltzmann Simulation of Pulsed Jet in T-Shaped Micromixer

Summary

A numerical study using the lattice Boltzmann method (LBM) is carried out to investigate mixing enhancement in a T-shaped micromixer using pulsed jet at low Reynolds number. The objective of this study is to determine whether the use of pulsed jet can enhance mixing. The same non reacting iso-thermal and incompressible fluid is used for the two fluid streams as our study focuses on the mixing through mechanical process (folding and stretching). Although diffusivity ultimately dictates the mixing at low Reynolds number, diffusivity is not an issue in our study as stretching and folding is independent of diffusivity. The simulation is carried out for single jet, opposite jets and parallel jets. Three dimensional study is also done where a combination of active (pulsed jet) and passive mixers (flat plate) are used to enhance mixing. For opposite and parallel jets configurations, simulations are done for inphase and out of phase jets. Study is also done varying the positions of the jets relative to each other. Pulsed jets seems to enhance mixing by creating vortical motion. These vortices increases the interfacial surface between the two streams, thus enhancing molecular diffusion.