Numerical and experimental investigations of air-flow and temperature patterns of a low velocity diffuser

In this article, four turbulence models are studied to capture the flow and temperature behavior of the air close to a low-velocity diffuser for displacement ventilation. Turbulence is modeled by means of one zero-equation model and three different two-equation models, i.e. the LVEL, the RNG, the Standard k-e, and the Chen-Kim model. They are evaluated for their performance in predicting the air flow patterns and temperature profiles close to the diffuser. The models are validated with measurements performed both with traditional point measuring techniques and a whole-field measurement method. The prediction of the velocity and the temperature by the three two-equation models is generally satisfactory. The predictions from the RNG and the Chen-Kim model were almost the same and slightly different than the standard k-e model. The RNG model and the Standard k-e model are computationally much more stable than the Chen-Kim model.