A model for investigating mixing speeds in suspended flows (Q1197498)

A model for evaluating the mixing speeds of suspended flows has been developed, which supports the following two conjectures: i) that there is an optimal circulation time distribution which minimizes the ratio of the time of mixing to that of average circulation, and ii) that the optimal time distribution is stable in the sense that distributions with similar features to the optimal one provide ratios that are close to the optimal one. This has been achieved by solving the model for a family of circulation time distributions. From this family, an optimal member is selected, and its mixing level is obtained as a function of time. The analysis also reveals two interesting features which slow down the mixing process. The mathematical model and its analysis in this interesting paper are based on the results obtained by \textit{R. Bowen} and \textit{D. Ruelle} [Invent. Math. 29, 181-202 (1975; Zbl 0311.58010)].