Figure 3.

The working mechanism of the contraction-obstacle design as simulated by a 2D periodic and pressure driven FENE-CR model using ${\eta }_s/({\eta }_p+{\eta }_s)=0.59,\hspace{0.17em}{a}_{\text{max}}^2=100$, and $\text{We}=21.3$ (based on the easy flow direction, see Sec. 4). The damping from the microchannel floor and ceiling is described with a shallow channel approximation. The velocity (a) and (c) as well as the trace of conformation tensor (b) and (d) are plotted for both flow directions. The predicted flow rate ratio is ${\text{Di}}_{\Delta p}=1.10$. The simulations were performed with 439k degrees of freedom with enhanced resolution at the obstacle separation points.