Simplification of local energy transfer theory of incompressible, isotropic, nonstationary turbulence

We show that the simplification or reduction of dimension in the local energy transfer (LET) theory of incompressible, isotropic, nonstationary turbulence can be achieved by using the transitive property of the propagator with respect to intermediate times along with the supplemental equation Q(k;t,t)=H(k;t,t('))Q(k;t,t') and not along with the Q(k;t,t')=H(k;t,t('))Q(k;t',t'), which has been suggested by Oberlack, McComb, and Quinn [Phys. Rev. E 63, 026308 (2001)]. Further, we point out that the analysis presented by Oberlack for the limiting case of viscosity approaching zero is incorrect and does not comply with the numerical solutions of LET theory.