Validation of Chymes: simulant studies Original Research Article

The CFD code Chymes models the initial mixing between core material and water in the lower plenum of a PWR. This paper reviews experiments to validate the code being carried out by Nuclear Electric and Oxford University. These experiments use isothermal and hot simulant fluids and particles in a thich-tank geometry to aid flow visualisation. Comparison with Chymes calculations (made at Culham Laboratory) shows that the code underpredicts the spreading in these experiments. It is believed that turbulent flow fields are assisting spreading, and that the accumulation of vapour in the wake of hot droplets may be increasing the coupling between the phases.