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Derivation and validation of a simplified analytical mass transfer model of the laminar co-flow tube for nucleation studies.
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SYSNO ASEP 0544195 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Derivation and validation of a simplified analytical mass transfer model of the laminar co-flow tube for nucleation studies. Tvůrce(i) Trávníčková, Tereza (UCHP-M) RID, ORCID, SAI
Havlica, Jaromír (UCHP-M) RID, ORCID, SAI
Kozakovič, M. (CZ)
Hrubý, Jan (UT-L) RID, ORCID
Ždímal, Vladimír (UCHP-M) RID, ORCID, SAIČíslo článku 121705 Zdroj.dok. International Journal of Heat and Mass Transfer. - : Elsevier - ISSN 0017-9310
Roč. 179, NOV 2021 (2021)Poč.str. 14 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova laminar co-flow tube ; atmospheric aerosol formation ; binary heteromolecular nucleation Vědní obor RIV DG - Vědy o atmosféře, meteorologie Obor OECD Environmental sciences (social aspects to be 5.7) Vědní obor RIV – spolupráce Ústav termomechaniky - Termodynamika CEP GA17-19798S GA ČR - Grantová agentura ČR LM2018122 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy Způsob publikování Open access s časovým embargem (01.12.2023) Institucionální podpora UCHP-M - RVO:67985858 ; UT-L - RVO:61388998 UT WOS 000706050900002 EID SCOPUS 85110769332 DOI 10.1016/j.ijheatmasstransfer.2021.121705 Anotace A laminar co-flow tube is a device recently developed by the present team to study the formation of aerosol particles in atmospherically relevant vapor mixtures. The device employs isothermal mutual dif- fusion of vapors in two merging laminar gas flows, each saturated with a different vapor. The main quan- tity of interest, namely, the nucleation rate at which aerosol particles are formed at given temperatures and vapor concentrations, is not measured directly. Therefore, a mass transfer model is needed to evalu- ate the local nucleation rate and local concentrations obtained from measured integral quantities the flow rates and vapor concentrations at the inlets and the number concentration of generated aerosol particles at the tube outlet. This article presents the derivation and testing of an analytical simplified mass transfer model in which the diffusion problem is solved with approximations for simplification. The purpose of the simplified model is to provide a tool suitable for experimental design and evaluation of results that does not require lengthy computations and transparently shows the effects of the main parameters. By idealizing the velocity field in the co-flow section as plug flow and neglecting axial dispersion, the gov- erning equations of mass transport reduce to a 1D unsteady 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 simplified mass transfer model is tested for particle formation in the sulfuric acid-water system. New experimental data for particle formation at temperatures of 15 ◦C and 27 ◦C at a relative humidity of 0.38 and various sulfuric acid concentrations are provided as a basis for testing. The results of the model are compared with numerical Computational Fluid Dynamics (CFD) simulations of the full mass and momen- tum transfer problem. The appropriate choice of plug-flow velocity for the analytical model is discussed. In this connection, hydrodynamics in the undeveloped region of the co-flow are described in detail. Based on the hydrodynamic entrance length, two essential fluid flow regimes are identified. The model results and CFD simulations show a nucleation zone with a shape resembling a candle flame located in the central part of the laminar co-flow tube, with a maximum nucleation rate at the tube axis. The main quantitative characteristics of the particle formation evaluated with the help of the simplified model and with CFD simulations are compared. It turns out that, especially when choosing the plug-flow velocity appropriately, the difference between the numerical CFD model and the simplified analytical model is less than the experimental uncertainty of the measured data. This justifies the application of the sim- plified mass transfer model for the purpose of quantitative evaluation of experiments with the laminar co-flow tube. This article presents new details of the mass transfer processes and evaluation procedures for the novel experimental device exemplified with a new set of experimental data for particle formation in a sulfuric acid-water system.
Pracoviště Ústav chemických procesů Kontakt Eva Jirsová, jirsova@icpf.cas.cz, Tel.: 220 390 227 Rok sběru 2022 Elektronická adresa http://hdl.handle.net/11104/0324159
Počet záznamů: 1