Plume rise from two or more adjacent stacks

Abstract Three studies are presented that investigate the effect of the number of stacks and of the azimuthal angle between the direction of the wind and the line of stacks on plume rise enhancement. In the first study, observations were made of the merger and motion of thermal pairs. Thermal pairs released in one-above-the-other configurations merged more rapidly and moved faster than thermal pairs released in a side-by-side configuration. In the second study, plume rise measurements were made in a wind tunnel for plumes from two to four stacks. For a given number of plumes, the rise was higher for those cases in which the azimuthal angle was small compared to cases with a larger angle. The third study was an analysis of data from Tennessee Valley Authority field studies. Due to large scatter and the small number of observations, the results are inconclusive for cases with two, three and four plumes. The ten plume cases clearly show higher rise and the rise is larger when the azimuthal angle is small.