\(P_{\text{GT}}{=\eta_{e}\eta_{m}\dot{m}}_{a}\left[\left(1+f+e\right)\overset{\overline{}}{C_{\text{pg}}}\left(T_{g3}-T_{g4}\right)-\frac{1}{\eta_{m}}\overset{\overline{}}{C_{\text{pa}}}\left(T_{a2}-T_{a1}\right)\right]\) \(\left(9\right)\)