The authors have investigated the effects of a slender recirculation region within the flow field on cross-stream heat or mass transport in the important limit of high Péclet number, where the enhancement over pure conductive heat transfer without recirculation is most pronounced. By employing matched asymptotic expansion, the authors have estimated the steady enhancement to resolve the diffusive boundary layers at the separatrices which bound the recirculation region.
This study is found most useful in many heat and mass transport devices which operate at high Péclet number. The authors claim that the chaotic enhancement can improve their performance and that a small amplitude theory can be used to optimise its application.