A systematic approach to describe the air terminal device CFD simulation for room air distribution analysis

Proper specification of air terminal device boundary conditions is the esse ntial element in accurate prediction of the air distribution in a ventilate d room. The conventional method of describing the air terminal device bound ary conditions requires large computing time, and some of the assumptions m ade are far from reality. This paper proposes a systematic approach that correctly and simply describ es the air terminal device boundary conditions for CFD simulation. Based on the detailed study of the air terminal device characteristics, the specifi cation of complicated air terminal device boundary conditions is transferre d to the specification of a volume around the diffuser. One surface of the volume will be located inside the jet main region. The boundary conditions of the volume are calculated using the diffuser jet characteristic equation s. This method was proved to be easy to use, more efficient, applicable to any type of diffusers and, above all, can correctly predict the airflow in a ventilated room. The predictions of the newly proposed method were compared with the predict ions of the conventional model as well as with the measured data. It is sho wn that the prediction of the new model is significantly more accurate than the prediction of the conventional model. (C) 2000 Elsevier Science Ltd. A ll rights reserved.