Modeling of the HESCO nozzle diffuser used in IEA Annex-20 experiment test room

The modeling of air supply devices has been identified from the IEA (International Energy Agency) Annex-20 project as one of the most important problems in applying computational fluid dynamics to predict air flow pattern and air distribution in buildings. In this paper, a simplified model for the modeling of the HESCO nozzle diffuser used in the IEA Annex-20 test room is tested and evaluated against experimental data. It is found that with the ReNormalization Group k– turbulence model and local mesh refinement, this model can give very good prediction of the wall jet flow issued from the diffuser. The influences of different numerical discretization schemes and turbulence models for the prediction of the wall jet flow are also investigated. Flow asymmetry phenomena observed both in numerical simulations and in experiments are discussed.