Spot ZO S1, S2 Experiments: Numerical Analysis by Computational Hydrodynamics

Computational hydrodynamics was used to perform, within the scope of the ERCOSAM–SAMARA international projects, calculations of the S1, S2 experiments on the SPOT ZO setup with a condenser-heat exchanger. The basic effects observed in the experiments are reproduced: helium pressure growth and stratification upon injection, pressure reduction and partial elimination of stratification during the operation of the condenser-heat exchanger. On the whole, the experiment agreed well with the calculations of the pressure, temperature, and composition of the gas. The small quantitative discrepancies with experiment indicate a possible impact of neglected factors, mainly, associated with inadequate knowledge of the details of the condensation/evaporation processes at and near the walls as well as with general sensitivity to variations of the initial conditions. Specifically, the deviation of the initial wall temperature or the total heat capacity of the wall appreciably influences the behavior of the pressure.