Ignition of a gas by a hot horizontal cylinder
The modern thermal theory of ignition makes the assumption that the substance in the heating zone is stationary. However, in describing the process of ignition in liquid and gaseous systems, this assumption is inadmissible. To fully take into account the effect of natural convection, it is necessary to jointly solve the equations describing the ignition process and the equations of motion. The authors consider the problem of the ignition of a chemically reacting gas by a cylindrical body in the presence of natural convection. In order to solve the equations of a nonstationary boundary layer, the method of successive approximations was used. The convective motion in a gaseous system transforms the temperature profiles in the preheating stage of ignition, leading to the localization of ignition. The heating wave is propagated around the circumference of the cylinder at the same time it moves into the medium. Natural convection affects ignition in other ways, influencing the nonstationary ignition characteristics in such a way that there is a considerable reduction in ignition lag as compared with the heat conduction case. It was found that the chemical reaction leads to an increase in the natural convection development time. This is associated with a decrease in the temperature drop between the heated cylindrical surface and the ambient medium, whose temperature rises as a result of chemical heat release.
- Research Organization:
- Chernogolovka
- OSTI ID:
- 6635583
- Journal Information:
- Combust., Explos. Shock Waves (Engl. Transl.); (United States), Vol. 18:4; Other Information: Trans. from Fizika Goreniya i Vzryva, Vol. 18, No. 4, pp. 11-16, Jul 1982
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
COMBUSTION KINETICS
NATURAL CONVECTION
GASES
IGNITION
BOUNDARY LAYERS
CYLINDRICAL CONFIGURATION
EQUATIONS
FLUID FLOW
HEAT TRANSFER
LIQUIDS
NUMERICAL SOLUTION
TEMPERATURE DISTRIBUTION
TEMPERATURE GRADIENTS
THERMAL CONDUCTION
THERMODYNAMICS
WAVE PROPAGATION
CHEMICAL REACTION KINETICS
CONFIGURATION
CONVECTION
ENERGY TRANSFER
FLUIDS
KINETICS
LAYERS
REACTION KINETICS
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry