Mixing flow of viscoelastic fluids in a microchannel
A solution with trace amount of deformable polymers, I.e. a viscoelastic uid, can exhibitelastic ow instability. However, the viscoelastic effects of a uid in a microchannel have only receivedattention recently. In addition, it appears that visco-elasticity has not been exploited effectively for the mixing of multiple uid ows. The complex interplay between the elasticity/viscosity of the uidsand the geometries of the channel is the key for efficient mixing of fluid streams in microchannels.Visco-elasticity allows a different approach for efficient mixing bypassing the limitation of the lowReynolds number in a microchannel ow. Here, we investigated the effects of uid viscoelasticityon the ow in a micro uidic with converging/diverging geometry. Efficient mixing of two dissimilarviscoelastic uids in a silicon-glass microchip was demonstrated. We observed that viscoelastic uidsmixing was achieved through elastically induced ow instability, which was triggered by an abruptcontraction, even at a very low Reynolds number (0 ￠10-2) and a large Peclet number (0 ￠107). Thisow regime had negligible inertial effects but significant elastic effects. Our results lay the foundationfor a simple yet efficient and pragmatic mixing mechanism.
micromixing viscoelastic microchannels flow instability non-Newtonian
Y.C.Lam H.Y.Gan N.T.Nguyen H.Lie
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798
国际会议
The Fifth International Conference on Fluid Mechanics(第五届国际流体力学会议)
上海
英文
2007-08-15（万方平台首次上网日期，不代表论文的发表时间）