What type of ignition system is used on most turbine engines?

What type of ignition system is used on most turbine engines?

• A. Low-energy coil ignition
• B. Electronically gated ignition
• C. High-intensity, intermittent-duty, capacitor discharge ignition
• D. Magneto-only ignition

Answer: (C)

Ignition systems in most turbine engines are built to deliver a strong, reliable spark precisely when light-off is needed, such as during start or a flameout recovery. A high-energy, intermittent-duty, capacitor-discharge ignition does this by storing energy in a capacitor and then dumping a large current through the igniter in a very short pulse. That rapid, high-energy spark is able to ignite the fuel-air mixture despite the harsh, high-velocity, high-temperature environment inside the combustor. The intermittent-duty aspect means the system fires only during start or when commanded, not continuously, which reduces wear and power draw while still ensuring ignition when required. Redundancy is also common, with multiple igniter plugs to ensure ignition even if one plug fails. Other options aren’t as well suited for turbine light-off: low-energy coil ignition is typical of some piston engines and wouldn’t reliably ignite in the turbine’s combustor conditions; magneto-only ignition is another piston-engine approach that relies on a magneto, not the capacitor-discharge method used here; and electronically gated ignition exists in some systems but is not the standard, widely used primary ignition method for turbine engines.

Ignition systems in most turbine engines are built to deliver a strong, reliable spark precisely when light-off is needed, such as during start or a flameout recovery. A high-energy, intermittent-duty, capacitor-discharge ignition does this by storing energy in a capacitor and then dumping a large current through the igniter in a very short pulse. That rapid, high-energy spark is able to ignite the fuel-air mixture despite the harsh, high-velocity, high-temperature environment inside the combustor.

The intermittent-duty aspect means the system fires only during start or when commanded, not continuously, which reduces wear and power draw while still ensuring ignition when required. Redundancy is also common, with multiple igniter plugs to ensure ignition even if one plug fails.

Other options aren’t as well suited for turbine light-off: low-energy coil ignition is typical of some piston engines and wouldn’t reliably ignite in the turbine’s combustor conditions; magneto-only ignition is another piston-engine approach that relies on a magneto, not the capacitor-discharge method used here; and electronically gated ignition exists in some systems but is not the standard, widely used primary ignition method for turbine engines.