The Effect of Pressure Variations on Premixed Flames
| Autor: | G. S. S. Ludford, Norbert Peters |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Asymptotic analysis
Chemistry General Chemical Engineering Enthalpy General Physics and Astronomy Energy Engineering and Power Technology Thermodynamics General Chemistry Lewis number Adiabatic flame temperature Physics::Fluid Dynamics symbols.namesake Fuel Technology Mach number Ordinary differential equation Thermal symbols Physics::Chemical Physics Pressure gradient |
| Zdroj: | Combustion Science and Technology. 34:331-344 |
| ISSN: | 1563-521X 0010-2202 |
| DOI: | 10.1080/00102208308923698 |
| Popis: | A thermal theory is developed to explain the experimentally observed effect of pressure changes on the propagation velocity of premixed flames. The theory uses a one-step reaction and large activation energy asymptotics in the framework of a slowly varying flame analysis. A one-dimensional unsteady flame with Lewis number ℒ equal or unequal to unity is considered. The Mach number is assumed to be low enough such that spatial pressure gradients can be neglected. The asymptotic analysis requires a small temperature variation of the unburnt gas due to pressure changes-this condition is satisfied in the limit of large heat release. The analysis shows that pressure changes affect the flame velocity in two direrent ways, through the change of the enthalpy balance in the preheat zone and through the change of flame temperature. An ordinary differential equation for the time variation of the normalized mass burning rate is derived. This equation is analysed for ℒ=l and constant relative pressure decrease... |
| Databáze: | OpenAIRE |
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