Benezech, Laurent Jean-Michel (2008) Premixed hydrocarbon stagnation flames : experiments and simulations to validate combustion chemical-kinetic models. Engineer's thesis, California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-05302008-113043
A methodology based on the comparison of flame simulations relying on reacting flow models with experiment is applied to C1–C3 stagnation flames. The work reported targets the assessment and validation of the modeled reactions and reaction rates relevant to (C1–C3)-flame propagation in several detailed combustion kinetic models. A concensus does not, as yet, exist on the modeling of the reasonably well-understood oxidation of C1–C2 flames, and a better knowledge of C3 hydrocarbon combustion chemistry is required before attempting to bridge the gap between the oxidation of C1–C2 hydrocarbons and the more complex chemistry of heavier hydrocarbons in a single kinetic model. Simultaneous measurements of velocity and CH-radical profiles were performed in atmospheric propane(C3H8)- and propylene(C3H6)-air laminar premixed stagnation flames stabilized in a jet-wall configuration. These nearly-flat flames can be modeled by one-dimensional simulations, providing a means to validate kinetic models. Experimental data for these C3 flames and similar experimental data for atmospheric methane(CH4)-, ethane(C2H6)-, and ethylene(C2H4)-air flames are compared to numerical simulations performed with a one-dimensional hydrodynamic model, a multi-component transport formulation including thermal diffusion, and different detailed-chemistry models, in order to assess the adequacy of the models employed. A novel continuation technique between kinetic models was developed and applied successfully to obtain solutions with the less-robust models. The 2005/12 and 2005/10 releases of the San Diego mechanism are found to have the best overall performance in C3H8 and C3H6 flames, and in CH4, C2H6, and C2H4 flames, respectively. Flame position provides a good surrogate for flame speed in stagnation-flow stabilized flames. The logarithmic sensitivities of the simulated flame locations to variations in the kinetic rates are calculated via the "brute-force" method for fifteen representative flames covering the five fuels under study and the very lean, stoichiometric, and very rich burning regimes, in order to identify the most-important reactions for each flame investigated. The rates of reactions identified in this manner are compared between the different kinetic models. Several reaction-rate differences are thus identified that are likely responsible for the variance in flame-position (or flame-speed) predictions in C1–C2 flames.
|Item Type:||Thesis (Engineer's thesis)|
|Subject Keywords:||Cantera; CH PLIF; ethane; ethylene; kinetic mechanism validation; methane; propane; propene; propylene; sensitivity analysis|
|Degree Grantor:||California Institute of Technology|
|Division:||Engineering and Applied Science|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||15 May 2008|
|Author Email:||benezech.laurent (AT) gmail.com|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Imported from ETD-db|
|Deposited On:||04 Jun 2008|
|Last Modified:||26 Dec 2012 02:49|
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