## 4 Discussion of Results  
Figure 4 elucidates the streamlines and isotherms of the liquid phase and the isotherms of the porous phase for the cases where \(Ra=10^{6},\;Ha=15,\;H=0.1\), \(\phi_{Al}=\phi_{Cu}=1\%\), \(\Phi=\frac{\pi}{3}\) and different inclination angles. As far as the streamlines are concerned, plots show a formation of two symmetric cells for an inclination angle of zero. The cell on the left hand side starts to dominate the region as the inclination angle increases. This is mainly due to the buoyancy forces. For the isotherms related to the fluid phase, plots show a formation of a hot thermal region near the fin. Moreover, plots show that for an inclination angle of zero, isotherms are symmetric throughout the centerline of the cavity with a maximum area covered by higher values of isotherms. As the angle increases, distortion of the isotherms happens as they shift counter clockwise. Additionally, it is obvious that as the inclination angle increases, less area of the domain is covered by higher values of the isotherms. Finally, the graph shows that for the porous phase, symmetric isotherms are observed for all inclination angles. Furthermore, as the inclination angle increases, the impact on the temperature distribution is very minimal as the porous temperature is not coupled with the velocity fields. Figure 5 illustrates features of the local entropy generation due to the fluid friction and local \(Be\) for the variation of the inclination angle \(\gamma\) (\(\gamma=0,\frac{\pi}{6},\frac{\pi}{3},\frac{\pi}{2}\)) at \(Ra=10^{6},\;Ha=15,\;H=0.1,\;\phi_{AI}=\phi_{Cu}=1\%,\;\Phi=\frac{\pi}{3}\). The graph shows that the \(\mathcal{S}_{t}\) decreases as the \(\gamma\) increases. The local entropy generation for \(\gamma\) equals zero appears to have the maximum values near the side walls. As the \(\gamma\) increases, this maximum value takes place at the upper wall of the cavity. Moreover, the graph shows that for \(\gamma\), \(Be\) less than 0.5 contours occupies most of the domain of the cavity; this is mainly due to the friction. Additionally, Be contours greater than 0.5 are observed at or near the sidewalls of the cavity as well as the fin walls. For these cases where \(Be\) is greater than 0.5, the entropy generation is mainly due to the transfer of heat. Figure 6 represents features of the streamlines and temperature distribution for the fluid phase and porous phase for the variation of the Hartmann number \(Ha\) (\(Ha=0,15,25,\)\(50,100\)) at \(Ra=10^{5},\;H=0.1,\;\phi_{Al}=\phi_{Cu}=1\%,\;\Phi=\frac{\pi}{3},\gamma=0\). The graph shows a formation of two symmetric cells inside the cavity as far as the streamlines are concerned. The  
intensity of the streamlines decreases as \(Ha\) increases. The magnetic field will suppress the flow and consequently lower values of the streamlines are observed by increasing \(Ha\). Moreover, the hot thermal regions are observed near the fin walls for both the fluid and porous temperature distributions. Finally, the graph shows a slight change in the temperature distributions with \(Ha\). Figure 6: Features of the streamlines and temperature distribution for the fluid phase and porous phase for the variation of the Hartmann number \(Ha\) (\(Ha=0,15,25,50,100\)) at \(Ra=10^{5},\ H=0.1\), \(\phi_{Al}=\phi_{Cu}=1\%\), \(\Phi=\frac{\pi}{3},\gamma=0\). \(Ha\) increases. Moreover, it is noted from \(Be\) contours and for all cases of \(Ha\) that the local entropy generation is dominated by the thermal component near the fin walls and at the corners of the cavity; while it is dominated by the friction at a small portion of the top wall of the cavity. Figure 7: Features of the local entropy generation due to the fluid friction and local Bejan number for the variation of the Hartmann number \(Ha\) (\(Ha=0,15,25,50,100\)) at \(Ra=10^{5},\ H=0.1,\ \phi_{Al}=\phi_{Cu}=1\%,\ \Phi=\frac{\pi}{3},\gamma=0\).