Hugoniot analysis of experimental data on steam explosion in stratified melt-coolant configuration

•Hugoniot analysis is applied to stratified steam explosion.•Incomplete participation of melt and coolant taken into account.•Peak pressures and conversion ratios are evaluated.•The model is shown to predict reasonably the steam explosion features. Recent experimental results on stratified steam explosion are analyzed by the model of “non-ideal” thermal detonation based upon Hugoniot relations, with factors taking into account incomplete melt fragmentation and participation of liquid coolant. The pressure behind the shock wave and conversion ratio are obtained as functions of the mass fraction of melt undergoing fragmentation and mass fraction of coolant in the explosion zone. Calculations are performed for one of the recent experiments on stratified steam explosion carried out with simulant oxidic materials. It is confirmed that the idealized scheme for thermal detonation overestimates significantly the conversion ratio, while predicting very low pressure levels. Taking into account incomplete melt fragmentation and limited participation of coolant improved the agreement between the predictions and experiments. Ranges for the melt fragmentation fraction and mass fraction of participating coolant where the model predictions agree with experimental values are obtained.