Wind tunnel investigation of natural ventilation through multiple stacks. Part 1: Mean values

Wind tunnel experiments have been performed on a scale model to study unsteady natural ventilation through multiple stacks. A previously developed hot-wire technique was used to obtain both mean and instantaneous flow characteristics. The work is described in two Parts. Part 1 concentrates on the mean flows, since it is these that are usually used for design purposes. Stacks are a potential means of ensuring that the required flow pattern is obtained over a range of conditions, so that flow direction (rather than just magnitude) is an important issue. Two distinct ways in which a wind tunnel can be used for design are considered. The first is to measure surface wind pressures, from which flow directions can be inferred or calculated. The second way is to carry out direct measurements of the stack flows (magnitude and direction). Both of these ways are examined using the measured data and their advantages and disadvantages are discussed.