Figure 4:

Two-dimensional velocity magnitude contours for (a) coronal and (b) sagittal planes in the iliac veins at resting and exercise flow rates. Flow profiles are extracted from the upstream portion of the planes (magenta lines), where the cross-sections are circular. Error bars represent local variability in the PIV velocity measurements (one standard deviation). Analytical fully-developed flow profiles at the nominal flow rates are plotted for comparison with the PIV velocity data. (*) Lower optical transparency in left iliac vein under the sagittal view results in loss of near-wall velocity vectors. This is possibly caused by incomplete wetting of the adhesive while assembling the inlet section (see Fig. 2b) or by imperfections in printing and polishing. A slight lateral shift of the laser sheet away from the intended bisection plane may have also occurred