Large-scale experiments and absolute detonability of methane/air mixtures.
Oran-ES; Gamezo-VN; Zipf-RK Jr.
Combust Sci and Technol 2015 Jan; 187(1-2):324-341
The Gas Explosions Research Facility at Lake Lynn Experimental Mines was used to determine the detonability limit of methane for a 1-meter diameter tube as a function of the percent of methane in air. The measurements showed detonation limits of 5.3% (lean) and 15.6% (rich). A method for extrapolating these limits to larger systems, more relevant to coal mine tunnels, was proposed based on a simple scaling law and some empirical information on the number of cells required for a detonation to propagate in closed, open, and partially open geometries. The scaling law reproduces the measured detonation-cell sizes measured in the 1-m tube. Applying this to a tunnel the size of a coal mine produces a detonability limit less than the currently measured flammability limit for methane/air at atmospheric conditions, which raises interesting questions for detonation and combustion theory and suggests measurements in larger tubes.
Gases; Explosions; Explosion; Explosive-gases; Methanes; Measurement-equipment; Coal-mining; Tunneling; Underground-mining;
Author Keywords: Absolute detonability; Detonation cell size; Explosion limits; Methane-air explosions; Methane detonability
E. S. Oran, Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, 4555 Overlook Ave. SW, Washington, DC 20375
Combustion Science and Technology