Keywords: concentration fluctuations, particle model, plume meandering, puff model, relative dispersion
Predicting concentration fluctuations with a puff-particle model
This paper demonstrates that the puff-particle model (PPM) allows for the prediction of concentration fluctuations (in addition to the estimation of the concentration itself). Several models have been developed based on Gifford's meandering plume concept to separate the dispersing effect of instantaneous plume (or puff) growth, and of meandering. They all have in common the assumption of a certain shape of the probability density function of concentration, and that the variance of concentration fluctuations is derived from the properties of turbulence. In contrast, the PPM aims at simulating a realistic 3-D meandering of the puffs, which allows for direct determination of the higher moments of concentration, whilst enabling the individual puffs to account for inhomogeneous conditions.