Prediction for vented explosions in chambers with multiple obstacles.

The predictive ability between existing models on explosion venting, such as the NFPA, Molkov and Yao equations, was examined against experimental data of peak pressures obtained in various chambers with internal obstacles. The NFPA equation yielded the highest overpressures in most cases. The Molkov and Yao equations obtained much better agreement with experiments. However, the statistical diagnosis of the data showed an underprediction of the pressures. This is undesirable for designing calculations where some margin of safety is preferable. A new empirical model derived for characterising chambers with internal obstacles correlated well with the data. In addition the new equation was further validated against a dataset published from the literature and also gave a good correlation.