Transfer of Particles in Nonisotropic Air Turbulence

Abstract

The inertia of particles is the basis of the present model of particle ?dry deposition? from a turbulent fluid. The basic physical concepts of particle thermal motion as described by Einstein are herein extended to describe the particle motion in nonisotropic turbulence in terms of a ?turbophoretic? velocity. The particle transfer from the turbulent fluid to a collecting black surface is therefore described in terms of a differential motion describing the chain of ?inertial flights? undergone by the particle under the gradient of turbulence velocity component in the direction of the collecting surface. This model of dry deposition shows satisfactory agreement with experimental values of particle deposition velocity as a function of particle size.