A CFD Model of a Swirl Diffuser for Heating and Cooling Modes

The aim of this study was to develop a simplified CFD model for the inlet jet of a swirl diffuser for the simulation of room airflow patterns. The swirl diffuser creates a complex flow pattern with high induction of room air, thus possessing a challenge for simulation. The studied diffuser was a model intended to be used in large enclosures. The flow pattern was adjustable between two basic modes: radial swirl jet for cooling conditions and compact downward swirl jet for heating conditions. For developing the CFD model, a series of laboratory measurements of the flow field was carried out.


How to model airflow discharged from diffuser is believed to be one of the key issues in ComputationalFluid Dynamics (CFD) applications to indoor air problem. Due to the complicated geometric feature andthe vortex-type airflow induced by swirl diffuser, simulating such a kind of diffuser is claimed to be achallenge. A simplified method of defining the boundary conditions at round swirl inlets is developedand introduced in this paper.