CFD-Simulations of Hydrogen Gas Explosion using the PDRFoam solver in OpenFOAM

Abstract

The gas, oil, and chemical industries face persistent threats from the accidental release of flammable gases, which can lead to catastrophic explosions. Hydrogen, increasingly popular as an alternative fuel, presents unique challenges due to its explosion hazards. Understanding and predicting the consequences of gas explosions are crucial for ensuring safety. This study utilizes computational fluid dynamics (CFD) simulations, specifically employing the PDRFoam solver within OpenFOAM, to assess the solvers capabilities of simulating hydrogen-air gas explosions in congested areas. The thesis focuses on two key aspects: ignition location and separating distance. In the analysis of ignition location, simulations reveal distinct behavior depending on the ignition point relative to the obstruction. Far-field ignition generates higher overpressure and velocity due to the fully developed flame upon reaching the congestion. Validations against physical experiments indicates that PDRFoam tends to overpredict the overpressure for these cases. Concerning separating distance, simulations demonstrate the flame behavior as it propagates through two identical obstructions. Cases with smaller separation distances results in unified flame propagation, where there is no deceleration phase in the open area between the two obstructions. PDRFoam overpredicts the overpressure in these scenarios, while underpredicting the overpressure in cases with larger separations, where a deceleration phase occurs.