Mini cross-flow

Fig. 4.6.1 (a) Di agram ofthe counterflow principle of membrane and dialysate flow in a hemodialyzer module, (b) Schematic depiction ofthe module cross section, (c-d) Photographs ofthe cross sections ofthe mini-hemodialyzer modules used in this study. 

Water (viscosity, // = 1 x 10 Pa-S) flows at 0.1 m /s through two rectangular channels (height = h and width = w) of same length but different cross-sections. The cross section of the micro channel and mini channel is given by (h = 100 im, w = 300 im (microchannel) and h=l mm, w = 3 mm (minichannel)). Calculate the ratio of viscous dissipation between the microchannel and minichannel. Discuss the important observa-tions/conclusions for design and analysis of microdevices based on the above calculation. 

---