Simultaneous Turbulent Momentum and Mass Transport in Swirling Flow of a Macroscale Multi Inlet Vortex Reactor

The production of uniformly sized functional nanoparticles for applications including pharmaceuticals, pesticides, and cosmetics is a problem of great interest. The macroscale multi-inlet vortex reactor (macro-MIVR) was developed for nanoparticle manufacturing through nanoprecipitation due to its ability to achieve rapid mixing and high efficiency. In the presented work, the turbulent momentum and mass transport in the macro-MIVR were investigated using simultaneous stereoscopic particle image velocimetry and planar laser induced fluorescence to determine flow statistics including turbulent viscosity, turbulent diffusivity, and turbulent Schmidt number. Measurements were performed in three planes located at different levels from the reactor bottom (¼, ½, and ¾) for Reynolds numbers of 3250 and 8125 based on reactor inlet mean velocity and hydraulic diameter.  The turbulent viscosity was found to be nearly axisymmetric about the center of the reactor, but both the turbulent diffusivity and turbulent Schmidt number varied with azimuthal position. For both Reynolds numbers, the turbulent viscosity and diffusivity are the highest in the vortex core near the reactor center. Finally, turbulent Schmidt number was found to vary between 0.02 and 0.7 throughout the reactor.