What energy transformation occurs in the starter system of a gas turbine?

The starter system of a gas turbine is responsible for initiating the engine's operation by providing the necessary mechanical energy to get the turbine rotating. This is typically done using either an electrical starter motor or a pneumatic starter, which uses compressed air.

In this process, electrical energy, when employing an electrical starter motor, or pneumatic energy, when using a pneumatic starter system, is transformed into mechanical energy. This mechanical energy is used to turn the turbine's rotor until it reaches the required speed for combustion and stable operation. This conversion is crucial because without the transformation of these forms of energy into mechanical energy, the gas turbine could not enter the operational phase where it generates the thrust or power needed.

Thus, the correct answer highlights the essential role of the starter system in facilitating the transition from the energy source—either electrical or pneumatic—to the functional state required for the gas turbine to operate effectively.