Figure 1.

Mouse endothelial cells shown in a (personal communication from A. R. Bond, Bristol Royal Infirmary, UK, 2007) appear approximately diamond-shaped (cleft entrances are stained dark using silver nitrate). Based on this observation, the cleft entrance structure can be approximated as a repeating diamond pattern (b), or even further simplified to an infinitely repeating array of infinitely long parallel outflow slits as shown in c. The simplified geometry (c) is characterized by only three parameters, namely the cleft half-width δ^∗, the cleft half-spacing Δ^∗, and the angle θ^∗ between the clefts and the applied flow. (Reused with permission from P. E. Vincent et al., Physics of Fluids, 20, 063106 (2008). Copyright 2008, American Institute of Physics.)