Validation of the Chymes mixing model Original Research Article

This paper contains a discussion of the work being performed in the UK to validate the Chymes coarse mixing model. Attention is focused on the Mixa experiments performed at Winfrith Technology Centre in which 3 kg of molten fuel simulant were released into water. The validation of Chymes against one of these experiments (Mixa06) is discussed in detail. It is concluded that Chymes can reproduce some features of the experiment (such as the existence of a steam chimney around the mixture and the steam production rate within a factor of two) but it does not predict the observed mixture development (the radial spreading and the deceleration of the first melt arriving at the surface) well. Additional model development and experimental analysis underway to resolve these differences is discussed.