# Influence of Micro-Textures on Cutting Insert Heat Dissipation
## 3 Experimental Study
### Experimental Device Validation  
Several tests were performed to evaluate the implemented experimental device. This involved the measurement of the inlet T1 and outlet T2 temperatures and the evaluation of the respective heat transfer rate for standard cutting inserts, by considering the input power levels of 100, 200, 300, and 400 W. Three experimental tests were made for each input power level, and the heat transfer rate was determined by Equation (1), in which the specific heat value of 4187 J/kg.K was considered. The averages and the standard deviation values (Avg \(\pm\) SD) for the inlet and outlet temperatures, the temperature gradient, the mass flow rate of water, and the heat transfer rate, for each input power level, are presented in Table 3.  
By comparing the heat transfer rate results in Table 3 with the ones in Table 2, one can confirm a high level of correlation between the experimental device and the numerical model, also revealing a linear trend with the input power. The maximum relative difference between the temperature measurements and simulations is 3%. The low standard deviation values presented in Table 3 prove the good reproducibility of the proposed experimental device and precise control of all variables.  
The temperatures measured by ten thermocouples during the heating phase for the 400 W input power are shown in Figure 7. This reveals that a steady-state thermal regime is only achieved 300 s after starting the heating phase. It is also observed that the maximum temperature occurs at the interface between the insert and the heat sources. At the base of  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Input Power [W]** & **T1 [°C]** & **T2 [°C]** & **\(\Delta\)T [°C]** & **Mass Flow Rate [g/s]** & **Heat Transfer Rate [W]** \\ \hline
100 & 15.68 \(\pm\) 0.11 & 16.89 \(\pm\) 0.10 & 1.21 \(\pm\) 0.01 & 15.64 \(\pm\) 0.0481 & 79.16 \(\pm\) 0.23 \\
200 & 15.74 \(\pm\) 0.11 & 18.04 \(\pm\) 0.11 & 2.29 \(\pm\) 0.01 & 15.58 \(\pm\) 0.0337 & 149.67 \(\pm\) 0.41 \\
300 & 15.50 \(\pm\) 0.35 & 18.91 \(\pm\) 0.34 & 3.40 \(\pm\) 0.01 & 15.57 \(\pm\) 0.0144 & 221.87 \(\pm\) 0.24 \\
400 & 15.62 \(\pm\) 0.32 & 20.19 \(\pm\) 0.33 & 4.57 \(\pm\) 0.01 & 15.64 \(\pm\) 0.0481 & 299.16 \(\pm\) 0.40 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Experimental thermal results for different input power levels.  
Figure 7: Temperature-time evolution during the heating phase, for the input power level of 400 W.  
the cutting insert is observed that the maximum temperature is close to 100 \({}^{\circ}\)C. As expected, the temperatures are higher for the thermocouples in direct contact with the cutting insert base (T3-T6), being slightly higher for the thermocouples near the heat sources (T3 and T4). It should be mentioned that similar temperature are observed between the two symmetry planes, i.e., ([T3 vs. T4), (T5 vs. T6), (T7 vs. T8), (T9 vs. T10)], which demonstrates good balance in the heat flow introduced by the two heat sources and the symmetry of thermal contact resistance between the pair of components.  
All these results allow to validate the implementation of the experimental device and support the performance of new studies to evaluate the heat transfer rate influence produced by the inclusion of micro-textures on the cutting insert surface.