effect of temporal modulation on the local kinematicprocess of two-dimensional chaotic flow:a numerical analysis

In this work, a numerical analysis based on cfd method is carried out to examine an unsteady laminar flowof newtonian fluids in a two-dimensional simulation of a mixer, which is composed of two rods inside amoving cylindrical tank. three stirring protocols are considered: non-modulated “nm”, continuouslymodulated “cm” and non-continuously modulated “alt” by using the dynamic mesh technique and userdefined functions “udf’s” for the velocity profiles. the chaotic advection is obtained by temporalmodulation of the rotational velocity of the cylinder and the rods to enhance the mixing of the fluid for verylow reynolds number. for this purpose, we applied the poincaré map as a reliable mathematic tool to checkmixing quality by tracking particles inside the fluid domain. additionally, we investigated the evolution oflocal flow proprieties such as rotation rate, deformation rate and elongation rate at different time periods inorder to see the effect of temporal modulation on the fluid kinematics. among the considered protocols, theresults of the mentioned simulation showed that it is possible to obtain a chaotic advection only for noncontinuouslymodulated protocol which enhance mixing fluid efficiency.