Simplified Numerical Models for Complex Air Supply Diffusers

Correct description of the flow and thermal information of an air supply diffuser is fatally important for a reliable prediction of room air distribution by using computational fluid dynamics. This study is to find simplified methods that can be used to describe flow and thermal information from eight commonly used diffusers. The investigation used the box and momentum methods. The corresponding experimental data of airflow and thermal distributions from an environmental chamber have been used to validate the numerical methods. The box method works for most of the diffusers with an appropriate box size. The momentum method performs well for five diffusers. Since the momentum method is simpler than the box method, the momentum method should be used, whenever it is applicable.