The modelling of stairwell flows

This paper extends an earlier investigation of scale effects on buoyancy driven recirculating flows in stairwells of the kind adopted in domestic accommodation. Further consideration is given to the role of Reynolds number, which proves to have unexpected features, possibly because stairwell flows fall into the range of incipient instability. A technique is developed to introduce explicitly the fraction defining the way in which the energy loss from the system is divided between the regions above and below the stairway. Finally it is shown that a single empirical constant suffices to complete relationships among key features of the processes of heat and mass transfer. The resulting formulae are suitable for incorporation within computer models of energy balances for complete buildings.