Derivation and validation of a simplified analytical mass transfer model of the laminar co-flow tube for nucleation studies
https://cesnet.zoom.us/j/95653379731
The laminar co-flow tube is a unique device developed at the Institute of Chemical Processes Fundamentals in cooperation with the Institute of Thermomechanics of the CAS to study homogeneous nucleation in binary and ternary mixtures. A simplified analytical model of mass transfer was derived and tested for this device. By idealizing the velocity field in the region of laminar co-flow by means of plug-flow and neglecting axial dispersion, the mass transport equations are reduced to a 1D non-stationary diffusion problem in cylindrical coordinates moving with the fluid. Such a simplified model has an analytical solution in the form of an infinite series. The suitability of the choice of plug-flow velocity for this model was discussed, and two basic modes of fluid flow were identified based on the hydrodynamic inlet length. The simplified mass transfer model should serve as a tool for experimental design and evaluation of results, which does not require lengthy calculations and transparently shows the influence of the main parameters. It was tested on the problem of homogeneous nucleation of aerosols in a sulfuric acid-water system. For testing purposes, newly measured experimental data were used for the formation of aerosol particles at temperatures of 15 ° C and 27 ° C, relative humidity of 38 %, and various concentrations of sulfuric acid. The results of the analytical model were compared with CFD calculations. It has been shown that the difference between the numerical CFD model and the simplified analytical model is smaller than the experimental uncertainty of the measured data, especially with a suitable choice of plug-flow velocity. This fact justifies using a simplified mass transfer model for the purpose of quantitative evaluation of laminar co-flow chamber experiments.
Trávníčková, T., Havlica, J., Kozakovic, M., Hrubý, J. and Ždímal, V.: Derivation and validation of a simplified analytical mass transfer model of the laminar co-flow tube for nucleation studies. Int. J. Heat Mass Tranf. 2021, 179, 121705. https://doi.org/10.1016/j.ijheatmasstransfer.2021.121705