Numerical Simulation of Hydrogen Deflagration Using CFD

Hydrogen is seen as an important future energy carrier as part of the move away from traditional hydrocarbon sources. Delayed ignition of a hydrogen-air mixture formed from an accidental release of hydrogen in either a confined or congested environment can lead to the generation of overpressure impacting both people and assets. An understanding of the possible overpressures generated is critical in designing facilities and effective mitigation systems against hydrogen explosion hazards. This paper describes the numerical modelling of hydrogen deflagrations using a new application PDRFOAM-R that is part of the wider OpenFOAM open-source CFD package of routines for the solution of systems of partial differential equations. The PDRFOAM-R code solves momentum and continuity equations, the combustion model is based on flame area transport and the turbulent burning velocity correlation is based on Markstein and Karlovitz numbers. PDRFOAM-R is derived from publicly available PDRFOAM tool and it resolves small and large obstacles, unlike PDRFOAM which is based on the Porosity Distributed Resistance approach. The PDRFOAM-R code is validated against various unconfined-uncongested and semi-confined congested explosion experiments. The flame dynamics and pressure history predicted from the simulation show a reasonable comparison with the experiments.