In the standard k-[epsilon] model, the eddy viscosity is determined from a single turbulence length scale, whereas in reality all scales of motion will contribute to the turbulent diffusion
. The above problems can be solved using the re-normalization group (RNG) k-[epsilon] turbulence model.
Bilger, "Turbulent diffusion
flames of hydrocarbon fuels stabilized on a bluff body," Symposium (International) on Combustion, vol.
where [bar.n](v) is the mean particle volume distribution function based on the volume and the last term on the left-hand side represents the change in [bar.n](v) resulting from turbulent diffusion
and is usually assumed to be :
From the analysis of Figures 3 and 4, it could be confirming the convenience of using a mass transport model without the turbulent diffusion
coefficient, described in Section 3.2.
where S [[ML.sup.3]] is the sediment volumetric concentration, y [L] is the vertical coordinate, [omega] [L/T] is the sediment settling velocity, and [[epsilon].sub.sy] [[L.sup.2]/T] is the sediment turbulent diffusion
coefficient along the y direction.
It can be stated, that the differences in the cycle dependent boundary conditions are not high enough to overcome the effects of the high turbulent diffusion
of a common (U)RANS model.
 reconstructed 2D O[H.sup.*] chemiluminescence distributions with a spatial resolution of about 1 mm in turbulent diffusion
flames with an exposure time of 200 [micro]s.
In the two-layer dry deposition model, in the upper layer, turbulent diffusion
dominates over molecular diffusion, and in lower layer the molecular diffusion dominates over turbulent diffusion
[45, 48, 49].
A number of investigations have been carried out for predicting turbulent diffusion
around buildings using wind tunnel tests [9,10].
There the turbulent kinetic energy of the dispersed phase, the coefficients of turbulent viscosity, and turbulent diffusion
of the particulate phase are respectively determined as follows:
The use of analytical models of turbulent flows and the presence of a set of exact solutions in particles~ dynamics opens the possibility to reach a deeper physical understanding of the nature of two-phase turbulent flows, and to use them for checking of numerical methods and turbulent diffusion
Especially the turbulent fields which are not always vital for the flowfield are equally important in the dispersion model as they are responsible for the turbulent diffusion