DET3D—A CFD tool for simulating hydrogen combustion in nuclear reactor safety

In this paper, the CFD code DET3D is described which has been used for simulating hydrogen detonations in complex three-dimensional geometries occuring in assumed accident scenarios in nuclear reactors.After a short description of the code, two validation calculations for DET3D against experiments are discussed in detail, both showing good agreement between calculation and experiment: (i) a hydrogen–air detonation in a 12 m long straight tube with a truely three-dimensional inner obstacle, and (ii) a pure radiolytic gas detonation in a 5 m long U-shaped tube at 44 bar initial pressure.As required by the ‘Best Practice Guidelines’ approach, results on the dependence of the computed solution on the mesh size, the numerical algorithm, and the chemical reaction scheme are also given. Whereas changing the mesh size is standard and easy to do with DET3D and can be used to establish numerical convergence, the influence of the other two features still needs further study.