Effects of pressure on structure and extinction of tubular flame

✍ Scribed by M. Nishioka; K. Inagaki; S. Ishizuka; T. Takeno

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 687 KB
• Volume: 86
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(91)90058-j

✦ Synopsis

A numerical study on effects of pressure on structure and extinction of a tubular flame was made. The adopted approach was the detailed kinetics theory combined with the exact similarity solution for the flow field. The calculation was made for stoichiometric methane-air mixture, and the structure and the extinction limits were determined for pressures ranging from 1 to 8 atm by using the so-called CI chemistry. It was found that at elevated pressures the flame radius is decreased because of the decrease in the burning velocity, while the reaction zone width is decreased due to the decelerated transport properties. The flame temperature is increased, approaching the equilibrium flame temperature due to the accelerated reaction rates. The extinction flame temperature increases, whereas the extinction flame radius decreases with pressure, with a minimum radius of around 0.2 mm at the highest pressure of 8 arm. The critical strain rate at extinction limit increases with pressure initially, reaching a maximum a~ around 2.7 atm and then decreasing for higher pressures. It appears that this behavior is closely related to the effects of curvature on extinction, which can be explained in terms of the simplified asymptotic analysis.