## 3 Results  
Figure 4 shows the velocity contour plots of all cases with and without implants in bifurcation and sidewall configurations. Due to the difference in peak velocity between the control case and the cases with implants, a logarithmic scale color map was used to enhance the comparison. In general, the figures show the effect of higher metal coverage on flow diversion by progressively reducing velocity within the aneurysm. Figure 4: _Cont._  
Table 2 shows the mean and maximum velocity measurements for each case and the percentage of reduction compared with the control case. As the metal coverage density increases, the mean and maximum velocities are reduced. The highest velocity reduction was observed in Case 4, the eCLIPs fourth-generation eBFD, which had the highest density. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Case** & **Density\%** & **Max. Velocity** & **Max Velocity** & **Mean Velocity** & **Mean Velocity** \\  & **(m/s)** & **Reduction (\%)** & **(m/s)** & **Reduction (\%)** \\ \hline Bifurcation & & & & & \\ \hline Case 1, no implant & N/A & 0.320 & N/A & 0.127 & N/A \\ Case 2, eBRS (Generation 2) & 26 & 0.0172 & 95 & 0.0049 & 96 \\ Case 3, eB (Generation 3) & 21 & 0.0260 & 92 & 0.0077 & 94 \\ Case 4, eBFD (Generation 4) & 35 & 0.0100 & 97 & 0.0014 & 98 \\ Case 5, PED 3.75 mm \(\times\) 18 mm & 30 & 0.0380 & 88 & 0.0075 & 94 \\ \hline Sidewall & & & & & \\ \hline Case 6, no implant & N/A & 0.0500 & N/A & 0.0096 & N/A \\ Case 7, PED 3.75 mm \(\times\) 18 mm & 30 & 0.0144 & 84 & 0.0013 & 86 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Peak and average aneurysm velocities and the percentage of reduction for each case at 300 mL/min volumetric flow rate. Figure 4: Velocity colour mapping and flow streamlines for different implants in sidewall and bifurcation geometry; note that logarithmic color mapping was used to enhance the comparison of contours. (**a**) Case 1, bifurcation, no implant, (**b**) Case 2, bifurcation, eBRS, (**c**) Case 3, bifurcation, eB, (**d**) Case 4, bifurcation, eBFD, (**e**) Case 5, bifurcation, PED, (**f**) Case 6, sidewall, no implant, (**g**) Case 7, sidewall, PED. Figure 4a shows the bifurcation aneurysm without an implant (control case). A jet was observed that entered the aneurysm predominantly from the distal end of the neck. The maximum velocity obtained was 0.32 m/s, which is significantly close to the theoretical velocity of 0.39 m/s calculated in the parent artery given the volumetric flow rate and model dimensions stated earlier. A considerable recirculation can be seen in the velocity map, with the core located near the top of the dome. For the eBRS implant (Figure 4b), the velocity was reduced across the dome, and there was no evidence of recirculation. The eB implant (Figure 4c) showed a similar flow pattern to the eBRS. However, a recirculation was observed, relatively weaker than that in the control case. The recirculation was counter-clockwise in the control case, while a clockwise recirculation was observed in the eB case. Amongst all the implants in the bifurcation configuration, the eBFD showed the best flow diversion performance and velocity reduction (Figure 4d). The maximum and mean velocity were reduced by 97% and 98%, respectively (Table 2). The velocity was significantly reduced at the dome, with no evidence of recirculation, and the highest velocity was observed at the sides of the neck. The PED in the bifurcation geometry (Figure 4e) showed a lesser level of flow diversion than the eBFD, and the mean velocity reduction was the same as that of eB (Table 2). The flow entered the aneurysm from the distal end of the neck with a relatively high core velocity. In the sidewall geometry without an implant, flow entered the aneurysm from the distal end of the neck, and a jet with a core velocity of 0.05 m/s was observed (Figure 4f). The flow circulated at the center of the aneurysm.