Chaotic mixing analyses by distribution matrices

Distributive fluid mixing in laminar flows is studied using the concept ofconcentration distribution mapping matrices, which is based on the originalideas of Spencer \& Wiley \cite{Spencer51}, describing the evolution of thecomposition of two fluids of identical viscosity with no interfacial tension.The flow domain is divided into cells, and large-scale variations incomposition are tracked by following the cell-average concentrations of onefluid using the mapping method of Kruijt et al. \cite{Kruijt2000}. An overviewof recent results is presented here where prototype two-- andthree-dimensional time-periodic mixing flows are considered. Efficiency ofdifferent mixing protocols are compared and for a particular example the(possible) influence of fluid rheology on mixing is studied. Moreover, anextension of the current method inclu! ding the microstructure of the mixture isillustrated. Although here the method is illustrated making use of thesesimple flows, more practical, industrial mixers like twin screw extruders canbe studied using the same approach