Unsteady flow effects due to fluctuating wind pressures in natural ventilation design - mean flow rates

The paper presents the results of a study into the effects of unsteady wind pressures on the mean flow rates in certain types of purpose-designed natu rally ventilated buildings. The study used nondimensional parameters and th e results should therefore cover a Ride range of conditions and should be o f general application. Tt is concluded that unsteady effects are restricted to a relatively narrow band of conditions. These conditions have been quan tified in terms of nondimensional parameters. In particular a simple proced ure for calculating the mean flow rates when the unsteady effects are large has been derived. In its simplest form the procedure does not require know ledge of the instantaneous wind pressures. (C) 1999 Elsevier Science Ltd. A ll rights reserved.