## 3 Results
### Performance Improvement  
As seen in previous studies [2; 3], the main effect of the injection is the deviation of the working flow from the suction side of the vane, which leads to a smaller flow section and increased velocities at the vane outlet. This effect can be determined from Figure 5, which presents the velocity contour at the mean radius of the vane before and after injection. The injection fluid interacts with the main flow creating a low-pressure zone downstream of the injection orifice, which leads to a decrease in the vane flow section and an acceleration of the working fluid. The decrease in flow section is visible when plotting the absolute pressure in the vane channels, as presented in Figure 6.  
Using this injection system for the previously presented partial regimes, it was determined that the generated power can be improved for a wide range of regimes. The results of the injection process are presented in Table 5. Graphically representing the regimes calculated before and after the injection, as in Figure 7, it can be observed, as in previous research, that there is an increase in the slope of the power generated by the turbine at different regimes. Thus, higher powers can be achieved without changing the turbine input parameters. In this way, the engine speed can be increased without adding fuel.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Case** & **Regime [\%]** & \(\hat{\text{M}}\) [kg/s] & \(\mathbf{P_{in}^{*}}\) [bar] & \(\mathbf{T_{in}^{*}}\) [K] & **Speed [rpm]** & **Power [KW]** \\ \hline Nominal & 100\% & 1.427 & 4.55 & 1180 & 45,000 & 274.3 \\ \hline Partial 1 & 71\% & 0.852 & 2.27 & 774 & 32,400 & 78.4 \\ \hline Partial 2 & 75\% & 0.936 & 2.5 & 798 & 34,200 & 96.6 \\ \hline Partial 3 & 80\% & 1.053 & 2.9 & 852 & 36,900 & 123.1 \\ \hline Partial 4 & 83\% & 1.093 & 3.04 & 876 & 37,800 & 136.8 \\ \hline Partial 5 & 85\% & 1.17 & 3.36 & 932 & 39,600 & 153.4 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Partial regimes’ parameters.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Measurement Unit** & **Value** \\ \hline Injection diameter \(\mathcal{O}_{\text{inj}}\) & mm & 0.5 \\ Number of orifices & - & 22 \\ Coverage degree & \% & 55.5 \\ Axial distance \(Za\) & - & 0.2 \\ Injection angle & \(\circ\) & 90 \\ Injection mass flow \(\dot{M}_{inj}\) & kg/s & 2.5\% \(\dot{M}\) \\ Injection total temperature \(T_{inj}^{*}\) & K & \(T_{inj}^{*}=T_{in}^{*}\) \\ \hline \hline \end{tabular}
\end{table}
Table 3: Injection system parameters.  
Figure 5: (**a**) Vane mean radius velocity distribution without injection; (**b**) vane mean radius velocity distribution with injection.  
Figure 6: (**a**) Vane mean radius absolute pressure distribution without injection; (**b**) vane mean radius absolute pressure distribution with injection.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Name** & **Regime [\%]** & \begin{tabular}{c} **Power without** \\ **Injection [kW]** \\ \end{tabular} & \begin{tabular}{c} **Power after** \\ **Injection [kW]** \\ \end{tabular} & \
\begin{tabular}{c} **Power** \\ **Injection [kW]** \\ \end{tabular} &
\begin{tabular}{c} **Equivalent** \\ **Increase [\%]** \\ \end{tabular} \\ \hline Partial 1 & 71 & 78.4 & 86.6 & 10.5 & 73 \\ \hline Partial 2 & 75 & 96.6 & 110.5 & 14.4 & 78 \\ \hline Partial 3 & 80 & 123.1 & 146.1 & 18.7 & 83 \\ \hline Partial 4 & 83 & 136.8 & 166.0 & 21.4 & 87 \\ \hline Partial 5 & 85 & 153.4 & 186.3 & 21.5 & 90 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Partial regimes’ analysis results.