Coffey C. J. , Hunt G. R.
Bibliographic info:
RoomVent 2004, 9th international conference in University of Coimbra - Portugal, 5-8th september 2004, pp 6, 3 Fig., 5 Ref.

We consider the overnight evolution of an initial two-layer thermal stratification (a warmupper layer and a cooler lower layer) in an enclosure ventilated via openings at high and low levels.Results of our laboratory experiments show that an efficient displacement flow is not always established and four distinct ventilation flow regimes are observed depending on the ratio R (= at /ab ) of the upper opening area, at , and lower opening area, ab ( > 0). For a given initial stratification, displacement flow is established only if R is sufficiently small (i.e. at