Turbulence and Dispersion


Atmosferic turbulence plays an important role in the study and the comprehension of fundamental processes involved in meteorology and dispersion. To obtain a reliable description of turbulence it is necessary to resolve a system of fluidodynamics equations using finite differences or more sofisticated numerical methods. In the models the properties of turbulence strongly depend on the “closure scheme” that is on the maximum order of the probability distribution moments of turbulent velocities considered.

The simpler schemes are essentially local and they can’t be applied over complex terrain. Therefore a realistic description of atmospheric turbulence requires a more sofisticated closure. Our group has developed models based on high order moments and has succesfully applied them demonstrating the fundamental role of the non-local transport terms in the dynamics of turbulence.

Concerning dispersion the group is devoted to the study of numerical lagrangian models reproducing the trajectories of particles either for absolute dispersion or for relative dispersion (two particle models). These models are based on the theory of Markovian stochastic processes.
All the models results are usually compared with theoretical profiles, obtained from the statistics, and with experimental measurments, obtained in water tanks or in wind tunnels.