Multiphase transients in the premixing of steam explosions

This paper describes the first attempt to experimentally quantify the multiphase transient associated with the premixing of steam explosions — a hot particulated (heavy) phase falling, in film boiling, into a coolant pool, which is thus forced to rapid vaporization. The process is characterized by mixing-zone-averaged and local void-fraction transients, as well as mixing-front advancement histories, and the data are found to be in good agreement with predictions carried out with our PM-ALPHA code. In particular, these tests confirm the predicted water depletion phenomenon which is a crucial factor in limiting the energetics of large-scale steam explosions.