Development of a simplified technique of modeling four-way ceiling air supply diffuser

Computational fluid dynamic (CFD) tools have been used extensively in the prediction of airflow in indoor environment. However, it is important to understand that the accuracy of such simulation is affected by a number of factors depending on micro- or macro-level of modelling. It is in the interest of this paper to study, in micro-level modelling, the impact of various description of air supply diffuser modelling on the accuracy of the airflow prediction. Air supply diffuser can be modelled in a number of different ways. Each technique can result in different airflow pattern around the diffuser and in the macro-environment. This paper investigates five different types of air supply diffuser modelling techniques. It compares the throw profile of each of these diffuser models against the measured profile in rooms of three different sizes. A diffuser modelling technique that uses the RNG k– turbulence model has been successfully developed. It is simple and yet without compromising on the accuracy of the predicted results