A Lagrangian Stochastic Model for the concentration fluctuations

[摘要] A Lagrangian Stochastic Model for the two-particles dispersion, aimingat simulating the pollutant concentration fluctuations, ispresented. Three model versions (1-D, 2-D and 3-D) are tested. Firstly theability of the model to reproduce the two-particle statistics in ahomogeneous isotropic turbulence is discussed, comparing the modelresults with theoretical predictions in terms of the probability densityfunction (PDF) of the particles separation and its statistics. Then, themean concentration and its fluctuations are considered and the resultspresented. The influence of the PDF of theparticle separation on the concentration fluctuations is shown anddiscussed. We found that the separation PDF in the inertial subrangeis not gaussian and this fact influences the predicted concentrationfluctuations.

[学科分类] 大气科学