## 3 Results and Discussions
### The Influence of Temperature and Velocity Contours on Hybrid Nanofluid Flow  
Figure 5 shows the temperature and velocity contours of hybrid nanofluid flow with VF of 0.4% at Re = 1000 and inlet temperature \(T_{in}\) = 323 K. Figure 5 shows that the corrugations make local breaks in the laminar sublayer and form local vortices, leading to an augmentation in the thermal characteristics of HNF flow within the elliptical channel. The Influence of Using Hybrid Nanofluid with Volume Fractions on Convective Heat Transfer at Various Reynold Numbers and Inlet Temperatures  
Figure 6 displays the outcome of the HNF with different VF on the convective HT coefficient for various Re and inlet temperature \(T\) = 313 K. For a given Re, the HT coefficient increases with increasing nanoparticle volume fraction, while the pure base fluid HT is between those at 0.1% and 0.2% VF. Fluid flow velocity increases with the Re, disturbing the flow and increasing the heat transfer rate. At Re = 1000, the maximum heat transfer coefficient, 2700 W/m\({}^{2}\)K, is achieved when the volume fraction of the EG/MgO-MWCNT nanofluid is 0.4%. The maximum value of the HT coefficient for a given Re corresponds to volume fractions of 0.4%, 0.2%, pure base fluid, and 0.1%, respectively. Figure 5: Temperature and velocity contours of hybrid nanofluid flow with VF of 0.4% at Re = 1000 and inlet temperature \(T_{in}\) = 323 K. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Temperature** & \multicolumn{4}{c}{**313 K**} & \multicolumn{4}{c}{**323 K**} \\ \hline \(\phi\) & EG & 0.1\% & 0.2\% & 0.4\% & EG & 0.1\% & 0.2\% & 0.4\% \\ \(k\) (W/m K) & 0.255 & 0.270 & 0.284 & 0.294 & 0.258 & 0.273 & 0.286 & 0.296 \\ \(\mu\) (Pa \(\cdot\) s) & 0.0102 & 0.0095 & 0.01005 & 0.0111 & 0.00745 & 0.0075 & 0.00755 & 0.0088 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Nanofluid thermophysical properties [57]. Figure 7 shows the influence of the HNF with different VF on the convective HT coefficient for various Re and inlet temperature \(T\) = 323 K. The ethylene glycol (EG) is considered the baseline. It is found that as Re increases, the average HT coefficient increases. Fluid flow velocity increases with the Re, disturbing the flow and increasing the HT rate. At Re = 1000, the maximum HT coefficient, 2480 W/m\({}^{2}\)K, is achieved when the volume fraction of the EG/MgO-MWCNT nanofluid is 0.4%. The maximum value of HT coefficient for a given Re corresponds to volume fractions of 0.4%, 0.2%, 0.1%, and pure base fluid, respectively. The Influence of Using Hybrid Nanofluid with Volume Fractions on the Ratio of Convective Heat Transfer to Base Fluid at Various Reynold Numbers and Inlet Temperatures  
Figure 8 presents the influence of the HNF with various VF on the ratio of the convective HT coefficient of the NF to that of the base fluid for various Re and inlet temperature \(T\) = 313 K. This figure shows that the use of the EG/MgO-MWCNT HNF with a volume fraction of 0.1% is reasonable at low Re. However, at high Re, the use of the EG is more efficient than that of the EG/MgO-MWCNT HNF with a volume fraction of 0.1%. It can be demonstrated that the use of the EG/MgO-MWCNT HNF volume fractions of 2% and 0.4% is more appropriate compared to the base fluid for all Re. Figure 6: Effects of using HNF with different VF on HT coefficient for various Re and inlet temperature \(T\) = 313 K.  
Figure 7: Influence of using HNF with different VF on HT coefficient for various Re and inlet temperature \(T\) = 323 K.  
Figure 9 presents the influence of the HNF with various VF on the convective HT coefficient for various Reynolds numbers and inlet temperature \(T\) = 323 K. It is observed that the use of the EG/MgO-MWCNT HNF with volume fractions of 0.1%, 0.2%, and 0.4% is more efficient than using the base fluid (EG) for all Re.