Publication: Premixed flames stabilized in narrow channels: Effect of chemical heat release on interfacial flame/wall energy transfer.
All || By Area || By Year| Title | Premixed flames stabilized in narrow channels: Effect of chemical heat release on interfacial flame/wall energy transfer. | Authors/Editors* | G.M.G. Watson and J.M. Bergthorson |
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| Where published* | Proceedings of the 2010 Spring Technical Meeting of the Combustion Institute/Canadian Section |
| How published* | Proceedings |
| Year* | 2010 |
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| Abstract |
This study investigates a ï¬ame stabilized in a channel with an axially varying wall tem- perature gradient. In this geometry, the tube diameter is of the same order as the ï¬ame thickness. Interfacial energy transfer between the gas and the wall is governed by the wall temperature and an axially developing thermal boundary layer. The thermal boundary layer has a dominant eï¬ect in the ï¬ame zone. The eï¬ect of non-linear heat release on the rate of interfacial heat transfer is studied experimentally and numerically to understand its eï¬ect on ï¬ame stabilization in narrow channels. In the experiment, a 1 mm quartz tube is heated by an external heat source forming the axial temperature gradient along the wall of the tube. The apparatus is designed to minimize the eï¬ect of heat recirculation while allowing the combustion wave to be studied visually. Stoi- chiometric methane/air ï¬ames are stabilized at diï¬erent positions along the wall temperature gradient over a range of inlet ï¬ow velocities. The ï¬ames are simulated with a numerical model that takes into account heat released due to chemistry and heat lost from the reaction zone due to enhanced heat transfer to the tube wall. In the model, the detailed structure of the ï¬ame is determined by employing a coupled numerical formulation which consists of a one-dimensional ï¬ame to model the axial diï¬usion and chemistry and a two-dimensional boundary layer to capture the eï¬ects of the boundary layer on ï¬ame/wall energy transfer. Results obtained from this model are validated against data obtained from the experiments to test the modelâs ability to predict trends in ï¬ame stabilization position. |
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