High performance in terms of thermal mixing of non-Newtonian fluids using open chaotic flow: numerical investigations

Kinematic Measurements of Novel Chaotic Micromixers to Enhance Mixing Performances at Low Reynolds Numbers: Comparative Study

“…The velocity field is strongly dependent on the components of the velocity gradient (∂ Ui )/(∂ xj ). Therefore, these components contribute to the kinematic flow of the fluid, such as vortex velocity, strain rate, rotation speed, and vortex stretch and compression [ 18 ]. It should be noted that these characteristics are almost negligible for a very slow regime (Re < 1), as the fluid flow is laminar and settling.…”

“…These operations damage the energetic boundary layers and limit their recovery. As the boundary layer is a barrier upon parietal heat transfer, its destruction considerably improves heat and mass transfer, especially on multi-layer micromixers [ 18 ]. These processes enhance the contact surface between the fluids to be mixed, even in the presence of the interfacial barrier as a surface tension [ 17 , 18 ].…”

“…As the boundary layer is a barrier upon parietal heat transfer, its destruction considerably improves heat and mass transfer, especially on multi-layer micromixers [ 18 ]. These processes enhance the contact surface between the fluids to be mixed, even in the presence of the interfacial barrier as a surface tension [ 17 , 18 ]. To define these behaviors, the coefficients of stretching and folding of the vortex α were investigated: where and are the vorticity vector and the deformation tensor, respectively.…”

“…For this purpose, chaotic micromixers can be a possible solution to increase both deformation and vorticity rates. These parameters are given in the following [ 18 , 19 ]: where ℧ presents the total fluid volume of the micromixer.…”

“…They found that the fluid homogenization rate enhances more than 200% by adding a direct current (DC) electric field inside the configurations. To characterize mixing efficiency with secondary flows, researchers use a different parameter focused on both fluid homogenization and fluid kinematic behavior for active [ 17 ] and passive mixers [ 18 , 19 , 20 ] called Local Physical Process (LPP) or kinematic measurements. They analyzed the behavior of the fluid in motion by calculating elongation, vorticity, helicity, stretching, and folding rates for different flow regimes.…”