The paper considers the equation for heterogeneity
coefficient within the turbulent mixing area in the approximation
of big Reynolds numbers and small Mach numbers. A mechanism
is studied of the heterogeneity coefficient dissipation
due to molecular diffusion. The Kolmogorov's hypothesis
on developed turbulence is used to calculate a dissipative
term. The model presented allows us to take into account
the heterogeneity degree in LV- and KE-models of turbulent
mixing. A system of equations allowing us to calculate
directly the heterogeneity degree is derived for the case
of the LV-model with the turbulent diffusion coefficient
which is constant over the turbulent mixing area. A self-similar
solution is derived for the heterogeneity coefficient which
is in good agreement with the results of experiments and
direct numerical simulations. The heterogeneity coefficient
averaged over the mixing area is shown to depend weakly
on the density drop between the mixing materials. Thus,
it is kH = 0.25 at the drop
n = 1–3, and at the drop n = 20 −
kH = 0.23.