Please use this identifier to cite or link to this item:
Title: Mixing characterization in different helically coiled configurations by laser-induced fluorescence
Author(s): Kováts, P.
Velten, C.
Mansour, MichaelLook up in the Integrated Authority File of the German National Library
Thévenin, DominiqueLook up in the Integrated Authority File of the German National Library
Zähringer, Katharina
Issue Date: 2020
Type: Article
Language: English
URN: urn:nbn:de:gbv:ma9:1-1981185920-660316
Subjects: Flow Mixing
Helically coiled configurations
Numerical simulations
Abstract: Flow Mixing of two miscible liquids has been characterized experimentally in three different helically coiled reactor configurations of two different lengths in the laminar flow regime at Re = 50…1000. A straight helical coil, a coiled flow inverter, and a new coiled flow reverser have been built, each in a 3-turn and a 6-turn configuration. Laser-induced fluorescence of resorufin has been used to visualize and quantify mixing in cross-sections throughout the reactors. A mixing coefficient is derived from the fluorescence images to allow for a quantitative measure and comparison of the six configurations. It becomes obvious from these experimental results, that an early flow redirection in the helical configuration is beneficial to mixing. The 3-turn reactors achieve nearly the same mixing coefficients as the 6-turn reactors with the double length. This can be explained by the stabilizing effect of the Dean vortices in the helix, which develop during the first two turns. After that, the liquid is trapped inside the vortices and further mixing is inhibited. Accordingly, the coiled flow inverter and coiled flow reverser configurations lead to much higher mixing coefficients than the straight helical coil. The results of these measurements are now used for validation of numerical simulations, which reproduce the geometrical and flow conditions of the experiments. Some exemplary results of these calculations are also shown in this article.
Open Access: Open access publication
License: (CC BY 4.0) Creative Commons Attribution 4.0(CC BY 4.0) Creative Commons Attribution 4.0
Sponsor/Funder: Projekt DEAL 2020
Journal Title: Experiments in fluids
Publisher: Springer
Publisher Place: Berlin
Volume: 61
Original Publication: 10.1007/s00348-020-03035-0
Appears in Collections:Fakultät für Verfahrens- und Systemtechnik (OA)

Files in This Item:
File Description SizeFormat 
Kováts et al._Mixing_2020.pdfZweitveröffentlichung4.64 MBAdobe PDFThumbnail