ABSTRACT
Turbulent diffusion is defined as the transportation of physical properties such as mass, heat, and momentum by the turbulent random motion of a fluid. Solid particle, mist, and small bubble cannot follow the fluid motion completely due to their inertia. The fluid fluctuating velocity is obtained by using a normal random function in which the average value is zero and the variance is equal to the fluid intensity. Substituting the fluid fluctuating velocity into the equation of particle motion, one can calculate the Lagrangian particle trajectory. Many researchers, for example Zaichik et al., developed the Eulerian model of particle diffusion called the diffusion inertia model based on a kinetic equation for the probability density function of particle velocity distribution. The merit of the Eulerian diffusion models is that the particle motion is expressed in terms of the carrier fluid.
