Modelling and speciation of nitrogen oxides in engines
| Autor: | Vincent Knop, André Nicolle, Olivier Colin |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Chemistry
Thermodynamic equilibrium Mechanical Engineering General Chemical Engineering Inorganic chemistry Thermodynamics Nitrous oxide Diesel engine Combustion chemistry.chemical_compound Relaxation (physics) Reactivity (chemistry) Nitrogen oxide Nitrogen dioxide Physical and Theoretical Chemistry |
| Zdroj: | Proceedings of the Combustion Institute. 34:667-675 |
| ISSN: | 1540-7489 |
| DOI: | 10.1016/j.proci.2012.06.082 |
| Popis: | The present study extends the Nitrogen Oxide Relaxation Approach (NORA [Vervisch et al., Combust. Flame 158 (2011) 1480–1490]) for NO x modelling in engines by introducing alternative chemical routes to the thermal pathway as well as a speciation of nitrogen oxides into nitrogen monoxide (NO), nitrogen dioxide (NO 2 ) and nitrous oxide (N 2 O). Perturbations of equilibrium state are considered to identify nitrogen oxide reactivity in various mixture and thermodynamic conditions. A common Intrinsic Low-Dimensional Manifold (ILDM) is identified for NO and NO 2 , while nitrous oxides appear to stay in near-equilibrium state for any in-cylinder conditions. The relaxations back towards the equilibrium state after the perturbations are analysed to extract the characteristic times of relaxation, an image of the species reactivity. Tabulation of equilibrium mass fractions and characteristic relaxation times as a function of mixture and thermodynamic conditions allows nitrogen oxide modelling to be performed for internal combustion engines at very low computational cost through idealised ILDMs that are independent of the combustion ones. Results show the accuracy of the modelling approach for nitrogen oxide emissions of a Diesel engine at part and full load. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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