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Prediction of Heat Transfer and Fluid Flow Effects on Entropy Generation in a Monolithic Catalytic Converter Using Large-Eddy Simulation

Li, Yongxiang ; Rico Cortes, Luis Felipe ; Hamel, Hardy ; Nishad, Kaushal ; Biondo, Luigi ; Ries, Florian (2022):
Prediction of Heat Transfer and Fluid Flow Effects on Entropy Generation in a Monolithic Catalytic Converter Using Large-Eddy Simulation. (Publisher's Version)
In: Entropy, 24 (5), MDPI, e-ISSN 1099-4300,
DOI: 10.26083/tuprints-00021283,
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Item Type: Article
Origin: Secondary publication DeepGreen
Status: Publisher's Version
Title: Prediction of Heat Transfer and Fluid Flow Effects on Entropy Generation in a Monolithic Catalytic Converter Using Large-Eddy Simulation
Language: English
Abstract:

In the present work, heat transfer and fluid flow and their effects on entropy generation in a realistic catalytic converter of a Lada Niva 21214 vehicle are studied using large eddy simulation. At first, the pressure drop over the catalytic converter is measured for dry air at constant temperature (T=298 K), different volumetric flow rates, and extrapolated to large volumetric flow rates for dry air (T=298 K) and for the exhaust gas under realistic engine conditions (T=900 K) using the Darcy–Forchheimer relation. Then, coupled heat and fluid flow phenomena inside the catalytic converter are analyzed for nonreacting isothermal conditions and nonreacting conditions with conjugate heat transfer by using the large-eddy simulation. The predicted pressure drop agrees well with the measured and extrapolated data. Based on the obtained numerical results, the characteristic flow features are identified, namely: the impinging flow with stagnation, recirculation, flow separation and laminarization within the fine ducts of the monolith, which depends on the heat transfer through temperature-dependent thermophysical properties of exhaust gas. Moreover, due to high-velocity gradients at the wall of the narrow ducts in the monolith, entropy production by viscous dissipation is observed predominantly in the monolith region. In contrast, entropy production due to heat transport is relatively small in the monolith region, while it overwhelms viscous dissipation effects in the pipe regions.

Journal or Publication Title: Entropy
Volume of the journal: 24
Issue Number: 5
Publisher: MDPI
Collation: 18 Seiten
Uncontrolled Keywords: catalytic converter, large-eddy simulation, entropy production, Darcy–Forchheimer relation, flow laminarization
Classification DDC: 600 Technik, Medizin, angewandte Wissenschaften > 600 Technik
600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften
Divisions: 16 Department of Mechanical Engineering > Institute for Energy and Power Plant Technology (EKT)
16 Department of Mechanical Engineering > Institute of Reactive Flows and Diagnostics (RSM)
Date Deposited: 06 May 2022 11:13
Last Modified: 06 May 2022 11:14
DOI: 10.26083/tuprints-00021283
Corresponding Links:
URN: urn:nbn:de:tuda-tuprints-212837
SWORD Depositor: Deep Green
URI: https://tuprints.ulb.tu-darmstadt.de/id/eprint/21283
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