The laboratory experience with IMRs was that the viscous systems
at Re < Rec could only be homogenized through a slow
diffusion process. The required long diffusion time process
is practically “infinitive” in the engineering sense, although
diffusion does eventually provide “complete” mixing between
IMRs and AMRs, and thus destruction of IMRs. This long
time scale, e.g. hours or days are often unacceptable when considering against the time scale of importance, e.g. a chemical
reaction, which may require a complete mixing in minutes.