Laminar mixing of high-viscous fluids by a novel chaotic mixer

In this study, an experimental examination of laminar mixing in a novel chaotic mixer was carried out by blob deformation method. The mixer was a circular vessel with two rotational blades which move along two different circular paths with a stepwise motion protocol. The flow visualization was performed by coloration of the free surface of the flow with a material tracer. The effects of significant parameters such as rotational speed of blades, blades length, and rotational speed amplitude on mixing efficiency and time were analyzed by measuring of the area covered by the tracer. The results revealed that increasing rotational speed intensifies stretching and folding phenomena; consequently, better mixing is obtained. Also, a better condition in flow kinematic was provided to blend, as stepwise motion protocol with wider amplitude applied. A reduction in mixing time could be observed while the blades with longer length were used. In addition, it was also found that the promotion of mixing by rotational speed is more effective than that of two other parameters. The quantitative data and qualitative observations proved the potential of the proposed chaotic mixer in the wide range of industrial processes including chemical reaction and food processing in which laminar mixing is required.