Lagrangian History Direct Interaction Equations for Isotropic Turbulent Mixing under a Second-Order Chemical Reaction

The Lagrangian history direct interaction approximation is applied to isotropic turbulent mixing of a second‐order chemical reaction, the resulting closed sets of equations are presented, and an a‐bridgement of them is carried out. It is shown that in the limit of a stochastically distributed second‐order reaction the equations reduce to those of direct interaction. It is also demonstrated that the approximation preserves an important property of the exact equations; namely, that in the absence of molecular diffusion, the decay of single point statistical functions of the concentration field is independent of the turbulence.