Hydrodynamics Flow in an Exocentric Input Dome T-Mixer (DTM)

Abstract

The mixing step of fluids at micro-scale is one of the most important operations in the development of micro-fluid systems in chemical reactors for applications in chemical and biochemical engineering, biomedical systems. The apparition of the cavitation phenomenon, in chemical precipitation reactors with rapid micromixing, can significantly affect the elaboration process. The bubbles appear in the reactive fluid flow when the local hydrostatic pressure decreases down to the liquid vapor pressure, which also corresponds to the maximum energy input producing the micromixing. In this article we report on a new T-mixer geometry with exocentric input of two reacting fluids for the preparation of homogeneous monodisperses nanoparticles. The inputs are in a perpendicular plane on the main output tube. The new T-mixer geometry (DTM) has a dome at the intersection of the two inputs. The dome affects the flow parameters: speed and pressure. We describe fluid dynamic calculations of water injection into a (DTM) at high Reynolds numbers up to 1.2 × 104. The fluid velocity profile shows an instantaneous formation of a vortex in the contact area at the fluids injection. The simulations are performed with the CFD software “Ansys Fluent”. Numerical calculations support the assignment to cavitation and show its critical relation to the (DTM) geometry.