# Effect of Structural Materials on Monopropellant Thruster Propulsion Performance in Micro Scale
## 3 Numerical Comparative Performance Analysis
### Gas and Materials Properties
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{3}{c}{_f(T) = C\({}_{6}\)T\({}^{6}\) + C\({}_{5}\)T\({}^{6}\) + C\({}_{4}\)T\({}^{4}\) + C\({}_{3}\)T\({}^{3}\) + C\({}_{2}\)T\({}^{2}\) + C\({}_{1}\)T + C\({}_{\theta}\)_} & & & & \\ \cline{3-8} \multicolumn{1}{c}{**Concentrations**} & \multicolumn{3}{c}{**Coefficients**} & & & & & \\ \cline{3-8} \multicolumn{1}{c}{**Concentrations**} & \multicolumn{3}{c}{**Co\({}_{6}\)**} & \multicolumn{3}{c}{**Co\({}_{5}\)**} & \multicolumn{3}{c}{**Co\({}_{4}\)**} & \multicolumn{3}{c}{**Co\({}_{3}\)**} & \multicolumn{3}{c}{**Co\({}_{2}\)**} & \multicolumn{3}{c}{**Co\({}_{1}\)**} & \multicolumn{3}{c}{**Co\({}_{\theta}\)**} \\ \cline{3-8} \multicolumn{1}{c}{**Concentrations**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{-13}\)**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{-10}\)**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{-12}\)**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{-4}\)**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{-1}\)**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{2}\)**} & \multicolumn{3}{c}{**Co\({}_{p}\)**: \(\times\)**10\({}^{4}\)**} \\ \multicolumn{1}{c}{**90\%**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-19}\)**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-15}\)**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-12}\)**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-9}\)**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-6}\)**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-4}\)**} & \multicolumn{3}{c}{**\(k\)**: \(\times\)**10\({}^{-2}\)**} \\ \multicolumn{1}{c}{**91**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-24}\)**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-20}\)**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-17}\)**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-14}\)**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-11}\)**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-8}\)**} & \multicolumn{3}{c}{**\(\mu\)**: \(\times\)**10\({}^{-6}\)**} \\ \hline \multirow{3}{*}{95\%} & \(C_{p}\) & 1.10128 & \(-\)4.94483 & 9.16607 & \(-\)8.98223 & 4.91171 & \(-\)1.41838 & 1.83952 \\  & \(k\) & 2.89022 & \(-\)1.36077 & 2.67550 & \(-\)2.83258 & 1.73078 & \(-\)4.83433 & 7.24316 \\  & \(\mu\) & 5.01273 & \(-\)2.70294 & 6.26318 & \(-\)7.89123 & 4.97555 & 2.80154 & 2.48434 \\ \hline \multirow{3}{*}{90\%} & \(C_{p}\) & 1.14765 & \(-\)5.15273 & 9.55068 & \(-\)9.35823 & 5.11684 & \(-\)1.47763 & 1.91276 \\  & \(k\) & 2.99845 & \(-\)1.41087 & 2.77169 & \(-\)2.93117 & 1.78915 & \(-\)5.02033 & 7.47042 \\  & \(\mu\) & 5.32318 & \(-\)2.87547 & 6.68007 & \(-\)8.46258 & 5.45069 & 2.58741 & 2.57703 \\ \hline \multirow{3}{*}{85\%} & \(C_{p}\) & 1.19401 & \(-\)5.36055 & 9.93516 & \(-\)9.73410 & 5.32189 & \(-\)1.53686 & 1.98596 \\  & \(k\) & 3.10478 & \(-\)1.46009 & 2.86620 & \(-\)3.02803 & 1.84651 & \(-\)5.20307 & 7.69370 \\ \cline{1-1}  & \(\mu\) & 5.62945 & \(-\)3.04568 & 7.09135 & \(-\)9.02626 & 5.91946 & 2.37615 & 2.66848 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Polynomial coefficients of the specific heat capacity, thermal conductivity, and dynamic viscosity of 85, 90, and 95 wt% hydrogen peroxide decomposed gas mixtures. Figure 3: Microthruster computational domain. (**a**) Hexahedral element fluid domain. (**b**) Tetrahedral element solid domain. For the simulation, six structural materials, namely glass, silicon, low-temperature co-fired ceramic (LTCC), high-temperature co-fired ceramic (HTCC), stainless steel, and copper, were considered. The first four materials were chosen since they have a wide range of applications in the engineering field of microsystems. The last two materials, common materials in engineering, were selected for comparison purposes.