## 3 Results and Discussions  
In the scope of this study, experiments were conducted by applying 12 different scenarios using two different cooling fluids at three different flow rates for two different \begin{table}
\begin{tabular}{c c c c} \hline
**Mesh Density** & **Number of Elements (Average)** & **Average \(Nu\)** & **Deviation from Previous Mesh (\%)** \\ \hline Very Coarse & 549,000 & 56.82 & - \\ Coarse & 876,000 & 61.45 & 8.15 \\ Medium & 1,338,000 & 62.73 & 2.08 \\ Fine & 1,965,000 & 63.16 & 0.68 \\ Very Fine & 2,855,000 & 63.31 & 0.24 \\ \hline \end{tabular}
\end{table} 
Table 4: Grid independence study. TPMS materials, and the results are presented in Table 5. Scenarios were carried out under turbulent flow at three different velocities for water and nanofluid as cooling fluids. The inlet temperature changed across experiments nevertheless, this variation was addressed by calculating the difference between the measured temperature and the specified inlet temperature. The experiments were conducted at three different flow rates: 23.56 cm\({}^{3}\)/s, 27.49 cm\({}^{3}\)/s, and 35.34 cm\({}^{3}\)/s. Data was recorded for each flow rate to investigate the performance of the system under varying flow conditions. The heat flux applied to the Al and Ag blocks was kept constant at 30.8 kW/m\({}^{2}\) throughout all experiments. Figure 4 shows the inlet temperature distribution of the fluid and the initial and boundary conditions for the test unit. Thermocouple is located 10 mm away from the point where the flow begins to enter the test section. When examining the temperature distributions of distilled water circulated through Al and Ag TPMS in Figure 4a,b, it was observed that the system reached a steady state within \(\sim\)25 min and there was a \(\pm\)0.5 \({}^{\circ}\)C difference in the initial inlet temperatures. Between each experiment, a waiting period of 4 h was allowed for the thermal loads on the setup walls to dissipate. Additionally, the slight fluctuations observed in the temperature curves were caused by small instabilities in the electric current. Figure 4c,d illustrate the inlet temperature distributions when nanofluids are utilized in Al and Ag TPMS structures, respectively. In experiments conducted at various flow rates (23.56 cm\({}^{3}\)/s, 27.49 cm\({}^{3}\)/s, and 35.34 cm\({}^{3}\)/s), inlet temperature variations in nanofluid systems were observed to remain within approximately \(\pm\)0.4 \({}^{\circ}\)C range. As demonstrated in Figure 4c, the implementation of nanofluids in Al TPMS structures provided more stable inlet temperature profiles compared to pure water. Similarly, as evidenced in Figure 4d, the utilization of nanofluids in Ag TPMS structures facilitated the system reaching steady-state conditions within approximately 20 min, with temperature fluctuations remaining minimal despite variations in flow rates. This phenomenon demonstrates the advantageous thermal stability characteristics offered by nanofluid implementation. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Scenarios** & **Material** & **Fluid** & **Flow Rate (cm\({}^{3}\)/s)** &
\begin{tabular}{c} **Inlet Temperature** \\ **(°C)** \\ \end{tabular} \\ \hline Scenario 1 & Al & Distilled water & 23.56 & 13.84 \\ Scenario 2 & Al & Distilled water & 27.49 & 13.62 \\ Scenario 3 & Al & Distilled water & 35.34 & 13.63 \\ Scenario 4 & Al & Nanofluid & 23.56 & 12.26 \\ Scenario 5 & Al & Nanofluid & 27.49 & 12.21 \\ Scenario 6 & Al & Nanofluid & 35.34 & 12.11 \\ Scenario 7 & Ag & Distilled water & 23.56 & 13.32 \\ Scenario 8 & Ag & Distilled water & 27.49 & 13.20 \\ Scenario 9 & Ag & Distilled water & 35.34 & 12.84 \\ Scenario 10 & Ag & Nanofluid & 23.56 & 13.67 \\ Scenario 11 & Ag & Nanofluid & 27.49 & 12.74 \\ Scenario 12 & Ag & Nanofluid & 35.34 & 12.20 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Scenarios applied in the experiments. Figure 4: _Cont._  
Figure 5 shows the experimental data for scenarios where distilled water was passed through the Al TPMS block.