Flux-gradient relationship for turbulent dispersion over complex terrain

F. Tampieri (1) , U. Giostra (1, 2) , F. Trombetti (2) , D. Anfossi (3) , E. Ferrero (4) , G. Tinarelli (5)

1 Istituto ISIATA/CNR
2 Istituto FISBAT/CNR
3 Istituto ICG/CNR
4 Dip. Scienze e tec. Avanz.
5 ENEL/CRAM

The transfer of a passive tracer in inhomogeneous turbulent flow is investigated. Starting from Lumley's constitutive equation, we derived an expression for the ratio between the effective eddy diffusivity K and eddy diffusivity K as a function of three length scales characterizing the local turbulence structure, flux variations and turbulence inhomogeneities. The theoretical predictions for the one-dimensional case of inhomogeneous symmetric turbulence were validated through a comparison with the numerical results of a Lagrangian particle model simulating a wind tunnel experiment of dispersion in the lee of an idealized two-dimensional hill. A qualitative agreement is reached between the theoretical evaluation of K and the value obtained from the numerical simulation.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]; Sciences de la Terre

F. Tampieri, U. Giostra, F. Trombetti, D. Anfossi, E. Ferrero, et al.. Flux-gradient relationship for turbulent dispersion over complex terrain. Nonlinear Processes in Geophysics, 1995, 2 (2), pp.89-100. ⟨hal-00301768⟩