TY - JOUR
T1 - Design method for micromixers considering influence of channel confluence and bend on diffusion length
AU - Aoki, Nobuaki
AU - Umei, Ryota
AU - Yoshida, Atsufumi
AU - Mae, Kazuhiro
N1 - Funding Information:
This research was supported by the New Energy and Industrial Technology Development Organization (NEDO) through the Project of Development of Microspace and Nanospace Reaction Environment Technology for Functional Materials.
Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/3/1
Y1 - 2011/3/1
N2 - In micromixers, fluids deform through convection generated by variations in the shape of a channel, e.g., channel confluence and bend. This deformation enhances the mixing performance of the micromixer. In this study, we consider the effect of deformation on mixing performance in terms of a reduction in diffusion length, which is equivalent to the size of the fluid segments formed through fluid deformation. Based on improvements in the mixing rate through convection, we establish a design method that enables a micromixer to achieve a desired rapid mixing rate. For this purpose, we correlate the mixing performance of micromixers having various channel shapes and fluid velocities with the diffusion length; the equivalent mixing rate is obtained using computational fluid dynamics (CFD) simulations. The results of the CFD simulations reveal that the combination of fluid collision and channel bend after the development of the velocity profile of confluent flow is effective at enhancing the mixing rate. To establish a design method for a micromixer, we define and employ the energy dissipation rate based on the pressure drop profile in microchannels. The relationship between the segment size and the energy dissipation rate based on channel shape has been derived and integrated into the design method.
AB - In micromixers, fluids deform through convection generated by variations in the shape of a channel, e.g., channel confluence and bend. This deformation enhances the mixing performance of the micromixer. In this study, we consider the effect of deformation on mixing performance in terms of a reduction in diffusion length, which is equivalent to the size of the fluid segments formed through fluid deformation. Based on improvements in the mixing rate through convection, we establish a design method that enables a micromixer to achieve a desired rapid mixing rate. For this purpose, we correlate the mixing performance of micromixers having various channel shapes and fluid velocities with the diffusion length; the equivalent mixing rate is obtained using computational fluid dynamics (CFD) simulations. The results of the CFD simulations reveal that the combination of fluid collision and channel bend after the development of the velocity profile of confluent flow is effective at enhancing the mixing rate. To establish a design method for a micromixer, we define and employ the energy dissipation rate based on the pressure drop profile in microchannels. The relationship between the segment size and the energy dissipation rate based on channel shape has been derived and integrated into the design method.
KW - Bend
KW - Computation fluid dynamics
KW - Confluence
KW - Diffusion length
KW - Energy dissipation rate
KW - Micromixer
UR - http://www.scopus.com/inward/record.url?scp=79952440049&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952440049&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2010.08.084
DO - 10.1016/j.cej.2010.08.084
M3 - Article
AN - SCOPUS:79952440049
VL - 167
SP - 643
EP - 650
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
SN - 1385-8947
IS - 2-3
ER -