Formation process of flame kernels produced by composite sparks in a quiescent propane-air mixture is numerically simulated by using a set of partial differential equations on two-dimensional cylindrical coordinates. Simulation is done with emphasis on physical effects such as gas movements generate
Spark ignition of combustible gas mixtures
โ Scribed by Eran Sher; James C. Keck
- Publisher
- Elsevier Science
- Year
- 1986
- Tongue
- English
- Weight
- 552 KB
- Volume
- 66
- Category
- Article
- ISSN
- 0010-2180
No coin nor oath required. For personal study only.
โฆ Synopsis
A mathematical model is presented to simulate the evolution with time of a spark channel into a combustion wave. The model considers the phenomena associated with electrical breakdown and arc phases, the plasma conductivity and realistic transport coefficients at high temperatures, and a detailed chemical reaction scheme. The growth of the initial flame radius is calculated by a numerical integration of the model equations and compared with the experimental observation of Tagalian and Heywood.
The time needed for the establishment of a flame propagation in the "like-laminar'" regime was found to be strongly dependent on the breakdown energy and on the spark duration, and to a small extent on the initial pressure, temperature, and residual gas fraction. The model was used also to examine quantitatively the effect of some relevant parameters on the cycle-to-cycle variation in the steady-state burning velocity and it was concluded that the cycle-tocycle variation is attributed mainly either to the inhomogeneity of the trapped mixture and/or to the cycle-to-cycle variation in trapped conditions; a variation of 5% of the volumetric efficiency affects the burning velocity by some _+13%.
๐ SIMILAR VOLUMES
Le'~ters to the Editors on points of .scientific interest rclatt'd to combustioa and flame are invited. The Editors do not hold themselves responsible for opinions expressed in correspondence, Anon.~mous contributiort,~ cannot be accepted.
A theoretical investigation of the ignition of a combustible gas by a heated vertical surface is described. Laminar, natural convection conditions were treated by numerical solution of the nonsimilar boundary layer equations, assuming an ideal gas and a one-step reaction and neglecting radiation. Th
This paper presents the results of a computational investigation of the process of deflagration to detonation transition in a combustible gas mixture. The type of combustion (i.e., deflagration or detonation) supported by a two-step reaction scheme is studied as a function of the activation energies