## 3 Materials and Boundary Conditions
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Property** & **AISI4340** & **AI2024-T81** & **AI7178-T6** & **In713 LC** & **TI-6 Al-4V** \\ \hline Young modulus & 205 GPa & 72.4 GPa & 71.7 GPa & 190 GPa & 113.8 GPa \\ \hline Density & 7850 kg/m\({}^{3}\) & 2780 kg/m\({}^{3}\) & 2830 kg/m\({}^{3}\) & 8000 kg/m\({}^{3}\) & 4430 kg/m\({}^{3}\) \\ \hline Yield strength & 862 MPa & 450 MPa & 540 MPa & 750 MPa & 873 MPa \\ \hline Poisson’s ratio & 0.29 & 0.33 & 0.33 & 0.382 & 0.342 \\ \hline Fatigue strength & \(\begin{array}{c}150\text{ MPa}\\ (1\times 10^{6})\end{array}\) & \(\begin{array}{c}125\text{ MPa}\\ (5\times 10^{8})\end{array}\) & \(\begin{array}{c}150\text{ MPa}\\ (5\times 10^{8})\end{array}\) & \(\begin{array}{c}150\text{ MPa}\\ (1\times 10^{9})\end{array}\) & \(\begin{array}{c}150\text{ MPa}\\ (5\times 10^{8})\end{array}\) \\ \hline Thermal conductivity & 44.5 W/(m.K) & 151 W/(m.K) & 125 W/(m.K) & 21.6 W/(m.K) & 6.7 W/(m.K) \\ \hline Specific heat & 475 J/(kg.K) & 875 J/(kg.K) & 856 J/(kg.K) & 648 J/(kg.K) & 526.3 J/(kg.K) \\ \hline Thermal expansion coefficient & 13.7 \(\mu\text{m}/(m.K)\) & 23.2 \(\mu\text{m}/(m.K)\) & 23.4 \(\mu\text{m}/(m.K)\) & 10 \(\mu\text{m}/(m.K)\) & 12.4 \(\mu\text{m}/(m.K)\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Basic properties at room temperature of the high-performance metallic alloys used. Figure 5: Working fluid pressures in measurement points at the compressor and turbine stages. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Local** & **Convective Coefficient (W/(m\({}^{+}\)C))** & **Temperature \({}^{\circ}\)C** & **Local** & **Convective Coefficient (W/(m\({}^{+}\)C))** & **Temperature \({}^{\circ}\)C** \\ \hline Turbine blade convex surface & 1265 & 706 & Compressor stator 4 blade surface & 2297 & 162 \\ \hline Turbine blade concave surface & 975 & 706 & Compressor stator 4 blade platform & 837 & 162 \\ \hline Turbine blade tip surface & 840 & 711 & Compressor stator 4 frontal surface & 744 & 154 \\ \hline Turbine blade platform & 839 & 699 & Compressor stator 4 back surface & 1111 & 169 \\ \hline Turbine disc frontal surface & 397 & 295 & Compressor stator 5 blade surface & 2561 & 206 \\ \hline Turbine disc back surface & 794 & 541 & Compressor stator 5 blade platform & 909 & 206 \\ \hline Compressor disc 1 blade surface & 1302 & 16 & Compressor stator 5 frontal surface & 933 & 200 \\ \hline Compressor disc 1 blade platform & 375 & 16 & Compressor top surface 1 st of 13 & 349 & 16 \\ \hline Compressor disc 1 blade type & 349 & 16 & Compressor top surface 2 nd of 13 & 370 & 23 \\ \hline Compressor disc 1 frontal surface & 319 & 15 & Compressor top surface 3 rd of 13 & 417 & 37 \\ \hline Compressor disc 1 back surface & 407 & 44 & Compressor top surface 4 th of 13 & 443 & 44 \\ \hline Compressor disc 2 blade surface & 1461 & 45 & Compressor top surface 5 th of 13 & 480 & 55 \\ \hline Compressor disc 2 blade platform & 464 & 45 & Compressor top surface 6 th of 13 & 538 & 77 \\ \hline Compressor disc 2 blade tip surface & 443 & 45 & Compressor top surface 7 th of 13 & 558 & 88 \\ \hline Compressor disc 2 frontal surface & 428 & 44 & Compressor top surface 8 th of 13 & 608 & 100 \\ \hline Compressor disc 2 back surface & 560 & 84 & Compressor top surface 9 th of 13 & 682 & 125 \\ \hline Compressor disc 3 blade surface & 1879 & 89 & Compressor top surface 1 th of 13 & 705 & 137 \\ \hline Compressor disc 3 blade platform & 575 & 89 & Compressor top surface 11 th of 13 & 762 & 150 \\ \hline Compressor disc 3 blade tip surface & 558 & 89 & Compressor top surface 12 th of 13 & 820 & 173 \\ \hline Compressor disc 3 frontal surface & 568 & 84 & Compressor top surface 13 th of 13 & 889 & 205 \\ \hline Compressor disc 3 back surface & 742 & 131 & Cover surface around compressor & 50 & 20 \\ \hline Compressor disc 4 blade surface & 2575 & 137 & Rear bearing seal & 300 & 130 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Heat transfer coefficients used in the computational simulations.