Abstract
An experimental investigation has been made on the concentration field dispersed from a ground-level point source in a turbulent boundary layer. Fluctuating concentration signals of ethylene are measured by a fast-response flame ionization detector (FID). The mean concentration profiles are well described by the Gaussian plume model with a modification of the exponent in the wall-normal direction. The cross-sectional distributions of the concentration fluctuation intensity show two maxima near the wall. It is found that the instantaneous concentration field spreads very widely compared with the mean field.
