Examination Of Thermal Detonation Codes And Included Fragmentation Models By Means Of Triggered Propagation Experiments In A Tin Water Mixture

In order to promote further discussions on thermal detonation descriptions of molten fuel/coolant interactions, thermal detonation codes developed at the IKE are applied to a recent experiment performed at the JRC in Ispra. In this experiment, 7.5 kg of molten tin at 1348 K were released into a vertical tube of phi 9.5 cm with a water column 109 cm high, preheated to 360 K. After triggering from the bottom, pressure waves propagated upwards through the premixture. The calculations demonstrate that, in principle, the effects observed can be explained by the theory. A strong, dominating contribution of thermal fragmentation mechanisms had, however, to be introduced in addition to hydrodynamic breakup. With this, a stable detonation wave as well as a quasi-steady case, overdriven due to triggering effects, were obtained as possible explanations of the experimental results. For the latter case, effects of locally varying premixture data have been studied because of remaining uncertainties in the experimental data.