Vented Explosion Overpressures From Combustion of Hydrogen and Hydrocarbon Mixtures

Experimental data obtained for hydrogen mixtures in a room-size enclosure are presented and compared with data for propane and methane mixtures. This set of data was also used to develop a three-dimensional gas dynamic model for the simulation of gaseous combustion in vented enclosures. The experiments were performed in a 64 m3 chamber with dimensions of 4.6 × 4.6 × 3.0 m and a vent opening on one side and vent areas of either 2.7 or 5.4 m2 were used. Tests were performed for three ignition locations, at the wall opposite the vent, at the center of the chamber or at the center of the wall containing the vent. Hydrogen–air mixtures with concentrations close 18% vol. were compared with stoichiometric propane–air and methane–air mixtures. Pressure data, as function of time, and flame time-of-arrival data were obtained both inside and outside the chamber near the vent. Modelling was based on a Large Eddy Simulation (LES) solver created using the OpenFOAM CFD toolbox using sub-grid turbulence and flame wrinkling models. A comparison of these simulations with experimental data is discussed.