# Impact of Plasma Combustion Technology on Micro Gas Turbines Using Biodiesel Fuels
## 3 Results and Discussion
### Compressor Outlet Pressure  
The operational pressures of the fabricated MGT engine, compressor, and auxiliary devices were determined using 5 VDC pressure gauges with specialized sensors made from a carbon steel alloy, with operation ranges between 0 and 2.4 MPa. Other pressures monitored included: pressure before compression, pressure after compression, fuel system pressure across all fuels (kerosene, diesel, and biodiesel), and engine oil system pressure. A hot-wire anemometer (AR866A hot wire anemometer) was used to measure the engine's air mass flow rate to illustrate the effect of plasma-assisted combustion technology on the MGT engine with a fixed fuel flow rate under varying loading conditions. The displayed result indicated constant flow rate values of 360, 460, and 565 mL/min for low, medium, and maximum loading operation conditions, respectively, for the fabricated MGT engine. The obtained output pressure result demonstrated a higher value under an external integrated plasma-rich fuel mixture than under normal working conditions and varied loading conditions (Table 6). The integrated plasma technology increases the compressor outlet pressure with increased in GTE loading across all applied fuels, as highlighted in green. Under normal and integrated plasma technology, the combustion-assisted kerosene presented the most elevated pressure: 11.83 (psi) and 12.02 (psi) under low loading conditions.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Mini GTE Loading**} & \multirow{2}{*}{**MGT Engine Operation Scenarios**} & \multicolumn{5}{c}{**Compressor Outlet Temperature Across Adopted Fuel**} \\ \cline{3-6}  & & & \multicolumn{3}{c}{**Samples (\({}^{\circ}\)C)**} & \\ \cline{3-6}  & & **Diesel** & **Kerosene** & **B20** & **B50** & **B75** & **B100** \\ \hline \multirow{2}{*}{Low} & Normal Operation & 107.6 & 105.5 & 101.7 & 99.9 & 100.9 & 107.3 \\ \cline{2-6}  & Plasma + Rich Mixture & 111.9 & 112.3 & 111.1 & 102.7 & 105.6 & 118.7 \\ \hline \multirow{2}{*}{Medium} & Normal Operation & 155.6 & 153.4 & 155.3 & 155.6 & 157.4 & 150.3 \\ \cline{2-6}  & Plasma + Rich Mixture & 162.6 & 164.6 & 157.7 & 160.4 & 159.3 & 156.4 \\ \hline \multirow{2}{*}{High} & Normal Operation & 199 & 185.6 & 195.3 & 195.9 & 200.1 & 206.7 \\ \cline{2-6}  & Plasma + Rich Mixture & 205.9 & 194.4 & 198.7 & 205.2 & 206.2 & 206.3 \\ \hline \hline \end{tabular}  
* In the Table 5, yellow highlights indicate the biodiesel improved value from integrated plasma and rich fuel mixture.  
\end{table}
Table 5: Compressor outlet temperature under different loading conditions.  
In contrast, under medium and high loading conditions, B75 presented the most elevated pressure of 21.48 (psi) and 32.2 (psi), respectively, under integrated plasma technology, as highlighted in green in Table 6. These values are higher than those obtained with other fossil fuels, as displayed in Figure 9. It can be deduced that all biodiesel fuel blends demonstrated exemplary performance in terms of wall pressure increase under medium and high loading conditions of the MGT engine at a low fuel injection flow rate (FFR). During this period, the B75 biodiesel blend from animal fat exhibited the best performance in terms of pressure increase, with a marginal flow rate compared to other fuel types.  
It can be deduced that all fuels demonstrated exemplary performance in terms of wall pressure increase at a low fuel injection flow rate. However, at higher injection FFR, the pure biodiesel (B100) exhibited the best performance in terms of pressure increase, with a marginal flow rate compared to other fuel types. All the fuels demonstrated a pressure increase increased injection FFR.