Numerical investigation of the effect of fan performance on forced draught air-cooled heat exchanger plenum chamber aerodynamic behaviour

The primary purposes of this numerical investigation is to determine to what extent the performance characteristics of a particular axial flow fan affects the plenum chamber aerodynamic behaviour of a forced draught air-cooled heat exchanger. An axial flow fan and heat exchanger model is implemented within a commercially available computational fluid dynamics code and combined to resolve the flow field through a range of forced draught air-cooled heat exchangers. It is found that a change in the angle at which the fan blades are set in the fan hub as well as the volume flow rate at which the fan operates affects the plenum chamber aerodynamic behaviour. It is further shown that the maximum possible recovery of kinetic energy within the plenum chamber does not necessarily coincide with the point of maximum fan static efficiency.