In a T-shaped mixer,the two liquid streams in the inlet channels meet each other at the T-junction,and their liquid-liquid contacting face exhibits planar,swirling folds and the folds breaking to be chaos and turbulen...In a T-shaped mixer,the two liquid streams in the inlet channels meet each other at the T-junction,and their liquid-liquid contacting face exhibits planar,swirling folds and the folds breaking to be chaos and turbulence,as the Reynolds number increases.The characteristic mixing scenario attracts long-time attention,given these mixings are of fundamental importance in fluid physics and also have been successfully used in engineering applications.The experimental and numerical studies of flow features and mixing characteristics in T-mixers are overviewed in this manuscript.This review introduces the experimental and numerical techniques in the studies,the flow and mixing characteristics in the corresponding regimes and application examples of the T-mixers at last,aiming at introducing fundamentals to researchers with initial interests on this topic.展开更多
Passive micromixers are preferred over active mixers for many microfluidic applications due to their relative ease in integration into complex systems and operational flexibility.They also incur very low cost of manuf...Passive micromixers are preferred over active mixers for many microfluidic applications due to their relative ease in integration into complex systems and operational flexibility.They also incur very low cost of manufacturing.However,the degree of mixing is comparatively low in passive mixers than active mixers due to the absence of disturbance in the flow by external forces and the inherent laminar nature of microchannel flows.Various designs of complex channel structures and three-dimensional geometries have been investigated in the past to obtain an efficient mixing in passive mixers.But the studies on mixing enhancement with simple planar geometries of passive mixers have been few and limited.The present work aims to investigate the possibility of mixing enhancement by employing simple planar type designs,such as T-mixer and T–T mixer with cylindrical elements placed in the mixing channel.The mixing performance has been evaluated in the Reynolds number range of 6 to700.Numerical results have shown that T–T mixer with cylindrical elements performed significantly well and obtained very good mixing quality over basic T-mixer for the entire range of Reynolds number(6 to 700).The device has also shown better mixing as compared to basic T–T mixer and T-mixer with cylindrical elements.A larger pair of vortices formed in the stagnation area due to the presence of a cylindrical element in the junction.Cylindrical elements downstream caused significant enhancement in mixing due to splitting and recombining action.The size of the cylindrical element in the T–T mixer has been optimized to obtain better mixing performance of the device.Remarkable improvement in mixing quality by T–T mixer with cylindrical elements has been obtained at the expense of small rise in pressure drop as compared to other passive designs considered in this study.Therefore,the current design of T–T mixer with cylindrical elements can act as an effective and simple passive mixing device for various micromixing applications.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11988102 and 92152106).
文摘In a T-shaped mixer,the two liquid streams in the inlet channels meet each other at the T-junction,and their liquid-liquid contacting face exhibits planar,swirling folds and the folds breaking to be chaos and turbulence,as the Reynolds number increases.The characteristic mixing scenario attracts long-time attention,given these mixings are of fundamental importance in fluid physics and also have been successfully used in engineering applications.The experimental and numerical studies of flow features and mixing characteristics in T-mixers are overviewed in this manuscript.This review introduces the experimental and numerical techniques in the studies,the flow and mixing characteristics in the corresponding regimes and application examples of the T-mixers at last,aiming at introducing fundamentals to researchers with initial interests on this topic.
文摘Passive micromixers are preferred over active mixers for many microfluidic applications due to their relative ease in integration into complex systems and operational flexibility.They also incur very low cost of manufacturing.However,the degree of mixing is comparatively low in passive mixers than active mixers due to the absence of disturbance in the flow by external forces and the inherent laminar nature of microchannel flows.Various designs of complex channel structures and three-dimensional geometries have been investigated in the past to obtain an efficient mixing in passive mixers.But the studies on mixing enhancement with simple planar geometries of passive mixers have been few and limited.The present work aims to investigate the possibility of mixing enhancement by employing simple planar type designs,such as T-mixer and T–T mixer with cylindrical elements placed in the mixing channel.The mixing performance has been evaluated in the Reynolds number range of 6 to700.Numerical results have shown that T–T mixer with cylindrical elements performed significantly well and obtained very good mixing quality over basic T-mixer for the entire range of Reynolds number(6 to 700).The device has also shown better mixing as compared to basic T–T mixer and T-mixer with cylindrical elements.A larger pair of vortices formed in the stagnation area due to the presence of a cylindrical element in the junction.Cylindrical elements downstream caused significant enhancement in mixing due to splitting and recombining action.The size of the cylindrical element in the T–T mixer has been optimized to obtain better mixing performance of the device.Remarkable improvement in mixing quality by T–T mixer with cylindrical elements has been obtained at the expense of small rise in pressure drop as compared to other passive designs considered in this study.Therefore,the current design of T–T mixer with cylindrical elements can act as an effective and simple passive mixing device for various micromixing applications.
