Calculation of the air flow pattern in a proposed new European test chamber for radiators.

A new European norm for measuring the heat transfer rate of radiators is under discussion [ CEN TC 130 ]. This testing can be done either in a closed chamber with cooled walls or in a open chamber with a controlled air supply. The air flow pattern around a typical radiator is calculated for both types of chambers. The calculation is done with the program PHOENICS, a finite volume program that solves the conservation equations for mass, momentum and energy. For turbulence, the k-E model is used with the Lam-Bremhorst correction for low Reynolds numbers. It has been found that the flow field around the radiator looks the same for both types of chamber. In the closed chamber there is a recirculating zone at the ceiling. This can be avoided in the open chamber when the air change rate exceeds some minimum value. This minimum value for the air change rate is dependent only on the heat output of the radiator.