Size scaling of gas explosions: Bruceton Experimental Mine versus the Lake Lynn Mine. Report of Investigations/1987

Single-entry gas-explosion characteristics for the Bruceton Experimental Mine (BEM) are compared to those occurring in the larger geometries of the new Lake Lynn Mine (LLM) within the Lake Lynn Laboratory. (All three are Bureau of Mines facilities). Scale factors and boundary conditions for the BEM and the larger entries of the LLM are reviewed in some detail using representative data for pressure, flame, and wind velocity in the two mines. Measured pressure histories for gas explosions at the BEM are compared with data for comparable explosions in the larger cross section of the LLM. The time evolution for flame-front displacment can be characterized by a general expression that relates gas concentration and length of flammable volume. The course of the explosion development and its destructive power are dependent upon the development of turbulence in the unburned flammable mixture into which the flame propagates. The results of the study indicated that pressure profiles in the larger cross section are maintained to much larger, distances even though the flame front is accelerated less rapidly in a comparable entry length of smaller flammable volume.