Eddy-Contact Micromixing

In which the source term, $S_O$ is Eqn. (3456).

• Kolmogorov Method

  $$\frac{1}{{\tau }_{turb}}=A\sqrt{\frac{\epsilon }{\nu }}$$

  (3487)

  Where $\epsilon$ is the turbulent dissipation rate, $\nu$ is the kinematic viscosity, and $A$ is a constant (mixing coefficient) with a default value of 0.04.

• Classical Scalar Dissipation

  $$\frac{1}{{\tau }_{turb}}=A{\frac{2+{Sc}^{-1}}{2}[\frac{1}{2}\frac{k}{\epsilon }+\frac{1}{2}\text{ln}\left(Sc\right)\sqrt{\frac{\nu }{\epsilon }}]}^{-1}$$

  (3488)

  Where $k$ is the turbulent kinetic energy, $A$ is a constant (mixing coefficient) with a default value of 1.0, and $Sc$ is the Schmidt number. Unlike gases, for liquids the molecular mixing is slow, which means that $Sc\gg 1$ .

The final reaction rate of species $i$ is the minimum of the mixing rate ${\tau }_{turb}$ that is calculated by Eqn. (3487) or Eqn. (3488) and the kinetic rate ${\dot{\omega }}_i$ that is calculated by Eqn. (3362).