Numerical Domain Reduction in Containment Atmosphere Mixing Simulations

Four experiments on mixing of stratified atmosphere, performed in the PANDA experimental facility with different jet injection velocities and atmosphere compositions, are simulated with the computational fluid dynamics code OpenFOAM. A 3D numerical model considering both vessels with interconnecting pipe is developed. Non-essential parts of the experimental facility, which do not contribute much to the mixing process, are identified according to experimental results. As the phenomena can be assumed to be axisymmetric, an axisymmetric 2D numerical model is proposed. Simulation results obtained with both numerical models are compared with experimental results and the effects of the use of smaller computational domain with axisymmetric boundary condition are studied.