Bechtel, Simon ; Bayer, Brian ; Vidaković-Koch, Tanja ; Wiser, Artur ; Vogel, Herbert ; Sundmacher, Kai (2024)
Precise determination of LJ parameters and Eucken correction factors for a more accurate modeling of transport properties in gases.
In: Heat and Mass Transfer = Wärme- und Stoffübertragung, 2020, 56 (8)
doi: 10.26083/tuprints-00023905
Artikel, Zweitveröffentlichung, Verlagsversion
 | Es ist eine neuere Version dieses Eintrags verfügbar. |
Kurzbeschreibung (Abstract)
The kinetic gas theory, in particular the equations of Chapman and Enskog, proved to be good and widely applicable approximations for modeling transport properties like diffusion coefficients, viscosities and thermal conductivities. However, these equations rely on at least the Lennard-Jones parameters and for polar gases also the dipole moment. In the scientific literature, the Lennard-Jones parameters are fitted to only one experimentally determined transport coefficient. This approach leads to good agreement between the Chapman Enskog equations employing the so obtained parameters with the experimental data for this specific transport property. However, utilizing the same parameters for modeling different transport properties oftentimes leads to distinct deviations. In this work, it is shown that the subset of Lennard-Jones parameters with which the Chapman Enskog equations can predict the experimental results with deviations comparable to the experimental uncertainty are not identical for each transport property. Hence, fitting towards one property doesn’t necessarily yield parameters that are suited to describe the other transport properties. In this publication, the Lennard-Jones parameters and a temperature dependent Eucken correction factor, leading to a significantly higher accuracy than the classical Eucken correction and also its modification by Hirschfelder, are therefore fitted towards all three transport properties simultaneously for seven exemplary gases. This approach leads to a significantly better agreement with experimental data for the three transport properties than the classical approach that relies on fitting to one single transport property and can be utilized to determine accurate sets of Lennard-Jones parameters and Eucken correction factors for any gas species. It provides a computationally inexpensive and practical method for the precise calculation of transport properties over a wide range of temperatures relevant for processes in the chemical industry.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2024 |
| Autor(en): | Bechtel, Simon ; Bayer, Brian ; Vidaković-Koch, Tanja ; Wiser, Artur ; Vogel, Herbert ; Sundmacher, Kai |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Precise determination of LJ parameters and Eucken correction factors for a more accurate modeling of transport properties in gases |
| Sprache: | Englisch |
| Publikationsjahr: | 30 April 2024 |
| Ort: | Darmstadt |
| Publikationsdatum der Erstveröffentlichung: | August 2020 |
| Ort der Erstveröffentlichung: | Berlin ; Heidelberg |
| Verlag: | Springer |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Heat and Mass Transfer = Wärme- und Stoffübertragung |
| Jahrgang/Volume einer Zeitschrift: | 56 |
| (Heft-)Nummer: | 8 |
| DOI: | 10.26083/tuprints-00023905 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/23905 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichung DeepGreen |
| Kurzbeschreibung (Abstract): | The kinetic gas theory, in particular the equations of Chapman and Enskog, proved to be good and widely applicable approximations for modeling transport properties like diffusion coefficients, viscosities and thermal conductivities. However, these equations rely on at least the Lennard-Jones parameters and for polar gases also the dipole moment. In the scientific literature, the Lennard-Jones parameters are fitted to only one experimentally determined transport coefficient. This approach leads to good agreement between the Chapman Enskog equations employing the so obtained parameters with the experimental data for this specific transport property. However, utilizing the same parameters for modeling different transport properties oftentimes leads to distinct deviations. In this work, it is shown that the subset of Lennard-Jones parameters with which the Chapman Enskog equations can predict the experimental results with deviations comparable to the experimental uncertainty are not identical for each transport property. Hence, fitting towards one property doesn’t necessarily yield parameters that are suited to describe the other transport properties. In this publication, the Lennard-Jones parameters and a temperature dependent Eucken correction factor, leading to a significantly higher accuracy than the classical Eucken correction and also its modification by Hirschfelder, are therefore fitted towards all three transport properties simultaneously for seven exemplary gases. This approach leads to a significantly better agreement with experimental data for the three transport properties than the classical approach that relies on fitting to one single transport property and can be utilized to determine accurate sets of Lennard-Jones parameters and Eucken correction factors for any gas species. It provides a computationally inexpensive and practical method for the precise calculation of transport properties over a wide range of temperatures relevant for processes in the chemical industry. |
| Freie Schlagworte: | Thermal conductivity, Diffusion coefficient, Viscosity, Kinetic gas theory, Lennard-Jones parameter, Eucken correction, Transport properties |
| Status: | Verlagsversion |
| URN: | urn:nbn:de:tuda-tuprints-239051 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 530 Physik 600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften und Maschinenbau 600 Technik, Medizin, angewandte Wissenschaften > 660 Technische Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Ernst-Berl-Institut 07 Fachbereich Chemie > Ernst-Berl-Institut > Fachgebiet Technische Chemie |
| Hinterlegungsdatum: | 30 Apr 2024 11:26 |
| Letzte Änderung: | 02 Mai 2024 07:41 |
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| Suche nach Titel in: | TUfind oder in Google |
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- Precise determination of LJ parameters and Eucken correction factors for a more accurate modeling of transport properties in gases. (deposited 30 Apr 2024 11:26) [Gegenwärtig angezeigt]
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