2134/34073
Ruipengyu Li
Ruipengyu
Li
Weeratunge Malalasekera
Weeratunge
Malalasekera
Salah Ibrahim
Salah
Ibrahim
Numerical study of vented hydrogen explosions in a small scale obstructed chamber
Loughborough University
2018
Hydrogen explosions
Flame-obstacle interaction
Dynamic LES model
Overpressure
Flame wrinkling
Mechanical Engineering not elsewhere classified
2018-07-23 12:34:28
Journal contribution
https://repository.lboro.ac.uk/articles/journal_contribution/Numerical_study_of_vented_hydrogen_explosions_in_a_small_scale_obstructed_chamber/9548552
There is a growing need to understand and estimate the explosion hazards associated
with hydrogen storage and utilisation. This paper presents a comprehensive numerical study on the explosion characteristics of a lean hydrogen-air mixture in a small-scale obstructed vented chamber. The large eddy simulation (LES) technique is employed to study the highly unsteady turbulence-driven explosion when the flame propagates past successive obstructions. A dynamic flame surface density
(DFSD) model is applied to the filtered chemical source term in the LES to account
for the progressive wrinkling of the deflagrating flame. The driving mechanism of
pressure rise and the underlying physics of flame-obstacle interactions are illustrated
using the detailed LES results. The paper considers 11 individual flow experimental
configurations of various obstacle number, size and location. They are further classified into six groups to investigate the influence of the level of blockage and the separation distance between adjacent obstructions. Critical safety-related parameters including the maximum overpressure and its incidence time are analysed. A comparison with propane is also made to highlight the substantial overpressure and flame acceleration of hydrogen deflagrations. Satisfactory agreements have been obtained between the LES and the experimental data, and this confirms the capability of the developed computational models in capturing essential explosion features and information for the study of vented hydrogen explosions.