Performance evaluation of empirical models for vented lean hydrogen explosions

This paper aims to provide a comprehensive review of available empirical models for overpressures predictions of vented lean hydrogen explosions. Empirical models and standards are described briefly, with discussion on salient features of each model. Model predictions are then compared with the available experimental results on vented hydrogen explosions. First comparison is made for standards tests, with empty container and quiescent starting conditions. Comparisons are then made for realistic cases with obstacles and initial turbulent mixture. Recently, a large number of experiments are carried out with standard 20-foot container for the HySEA project. Results from these tests are also used for model comparison. Comments on accuracy of model predictions, their applicability and limitations are discussed.A new model for vented hydrogen explosion is proposed. This model is based on external cloud formation, and explosion. Available experimental measurements of flame speed and vortex ring formation are used in formulation of this model. All assumptions and modelling procedure are explained in detail. The main advantage of this model is that it does not have any tuning parameter and the same set of equations is used for all conditions. Predictions using this model show a reasonably good match with experimental results.