Simplified numerical models for complex air supply diffusers

Correct description of the flow and thermal information for an air supply diffuser is important for reliably predicting room air distribution by using computational fluid dynamics. Simplified methods that can be used to describe flow and thermal information from eight commonly used diffusers were developed in this study. The investigation used the box and momentum methods. The corresponding experimental data on airflow and temperature distributions from an environmental chamber have been used to validate the numerical methods. The box method with an appropriate box size is satisfactory for most of the diffusers. The momentum method performs well for five diffusers. Because the momentum method is simpler than the box method, the momentum method should be used whenever it is applicable.