The second input for the integration is ambient temperature as in Fig. \ref{318286}. The value is at 80 in midnight and increases to a peak at 96\(^{\circ}\)F during the daytime. This is the actual temperature in Malaysia and the profile is almost the same each day due to the climate condition in the country. This input is fed to Rowen’s model alongside with the actual load demand to simulate main and pilot gas fuel valves, engine gas fuel flow and temperature average signals .