Pressure rise generated by the expansion of a local gas volume in a closed vessel

Abstract

Experiments were conducted to determine the pressure rise that results from either the combustion of a localized gas volume or the expansion of a pressurized gas volume adjacent to an inert gas in a closed vessel. The experiments consisted of either pressurized air or the combustion of stoichiometric and fuel-lean hydrogen-air mixtures compressing an inert gas. The pressure rise in the inert gas was measured as a function of either the volume fraction or the initial pressure of the expanding gas. Helium, nitrogen, air and carbon dioxide were tested to explore the effect of inert gas heat capacity on the pressure rise. The final pressure of the inert gas increased with the volume fraction and initial pressure of the expanding gas, and was influenced to a lesser extent by the heat capacity of the inert gas. A model was assessed using the experimental data, and the theoretical results were consistent with the observed trends. This model and other published models were assessed and compared using prior data for localized gas combustion surrounded by an inert gas and the partial combustion of homogeneous methane-air mixtures.

Deflagrations of localised homogeneous and inhomogeneous hydrogen-air mixtures in enclosures

“…Stamps et al reviewed publications on combustion of localised mixtures in closed vessels [5]. Theoretical work on dynamics of partial combustion in a closed vessel was traced back to work by Flamm and Mache [6], and Lewis and von Elber [7].…”

“…The paper aims to develop and validate novel engineering models for localised deflagrations in closed and vented enclosures. The thermodynamic model for localised uniform mixture deflagration overpressure in a closed building is validated against experimental data [5]. Validation of the model for localised uniform and non-uniform vented deflagration is carried out against unique experiments with hydrogen-air mixtures in two enclosures: 1 m 3 volume chamber at Karlsruhe Institute of Technology (KIT, Germany) [28], and in 31 m 3 volume container at Health and Safety Executive (HSE, UK) [24].…”

“…Stamps et al [5] conducted experiments on combustion of localised hydrogen-air mixtures in the closed constant volume vessel. The vessel in the form of pipe was filled in partially by hydrogen-air mixture separated by a piston from an inert gas (carbon dioxide, helium, nitrogen).…”

“…Experimental measurements [5] included burnt mixture pressure 1 b p , for which a companion set of constant volume combustion tests was conducted filling the entire vessel with hydrogen-air mixtures. Table 1a gives comparison of the model solution ( 7) against experimental data [5] for varying flammable volume fraction  with constant hydrogen-air equivalence ratio 0.997 using experimental data on 1 b p . Table 1a shows also predictions by the model of Boyack et al [10] as done in [5].…”

“…Table 1a gives comparison of the model solution ( 7) against experimental data [5] for varying flammable volume fraction  with constant hydrogen-air equivalence ratio 0.997 using experimental data on 1 b p . Table 1a shows also predictions by the model of Boyack et al [10] as done in [5]. The Ulster model scatter in prediction of 2 p is closer to experimental data while predictions by [10] are shifted to higher overpressures.…”