Abstract
Fast liquid mixing in the flow channels at millimeter size was studied by planar laser induced fluorescence (PLIF) technique in experiments and the large eddy simulation (LES) as well. A simplified mixer model was applied, where two liquid streams impinge into each other in the confined channels. A dynamic kinetic energy sub-grid scale (SGS) model of LES was employed to simulate the fast liquid mixing. The results show that LES predictions with high-density meshes have good agreement with the experimental data in terms of the instantaneous and time-averaged concentration fields, and the probability density function (PDF) of concentration fluctuations. Hence, the mixing quality characterized by the intensity of segregation (IOS) and 95% mixing time can be also predicted reasonably. The LES simulations further predict the significant effect of cross-flow angle on the mixing process. The cross-flow angle of 90 ∘ gives the fastest mixing of two liquids in the millimeter channels at 1–2 ms. The mixing layer between the two liquid streams cannot be observed under the geometry with larger cross-flow angles. This indicates different mixing mechanisms compared with the mixing of two liquids flowing in parallel. Vorticity in the turbulent mixing process is discussed for a better understanding on the physical factors controlling the mixing process.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.