Unsteady flow effects due to fluctuating wind pressures in natural ventilation design—instantaneous flow rates

The paper presents the results of a theoretical study into the effects of unsteady wind pressures on the instantaneous flow rates in certain types of purpose-designed naturally ventilated buildings. The study used nondimensional parameters and the results should therefore cover a wide range of conditions and should be of general application. The main concern is with the potential for reducing the occurrence of instantaneous flow reversal through openings, by the use of long ducts instead of sharp-edged openings. It is concluded that substantial benefits can be achieved and the required conditions are defined in nondimensional terms.