Probability distributions of dispersion from a model plume in turbulent wind

Wind tunnel experiments were performed to measure mean, standard deviation and peak mass concentrations of a discharge at vertical and horizontal traverses downstream of a model stack. Time series data of concentration fluctuations measured from ten fast response flame-ionisation-detectors were collected for statistical analysis. The measurements were made for a single buoyant and non-buoyant model phime source discharged from a stack with two exit velocities in neutral, suburban terrain roughness turbulent wind flows. With the inclusion of a building placed between the stack and the measurement locations, the effects of the interaction with the building wake were also examined. Cumulative probability distributions presented in Weibull plots have shown the relatively higher intermittency characteristics of dispersion at the extremities of a plume close to the stack source. At distances further away from the stack, the intermittency of the plume has been shown to become lower.