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:
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