Examples of critical flight modes that use continuous ignition are takeoff, landing, and some abnormal and emergency situations. Most gas turbine engines are equipped with a high-energy, capacitor-type ignition system and are air cooled by fan airflow.
What is continuous ignition?
In a jet engine, the term “continuous ignition” refers to both automatic and pilot selectable activation of the ignition system in circumstances other than during the start cycle. … Once the engine is started, combustion is self sustaining so long as fuel is supplied and the airflow is not interrupted.
What are two types of ignition systems used in turbine engines?
Furthermore, the different types of ignition systems can be broken down into two categories: low-tension ignition systems and high-tension ignition systems. The heart of every turbine ignition system —both high and low tension — is the exciter, an engine- or airframe-mounted hermetically-sealed electrical box.
What are the four continuous events that take place in a turbine engine?
A more recent term is “continuous combustion cycle.” The four continuous and constant events are intake, compression, expansion (includes power), and exhaust. These cycles are discussed as they apply to a gas-turbine engine.
Why does ignition continue once igniters are turned off?
Once the igniter lights the fire, it is self-sustaining, and the igniter is turned off. When jet engines experience a temporary disturbance of constant airflow, they can flame out. The fuel to air mixture needs to remain within close parameters for a self-sustaining flame.
What is the difference between spark plug and exciter plug?
The exciter uses input power from an airframe electrical bus or an engine-mounted generator to convert relatively low voltage to more useable, high-voltage energy pulses that fire an igniter plug and in turn ignite the fuel/air mixture. … Spark plugs are used to detonate the air/fuel mixture in each cylinder.
How many igniters are used in most turbine engines?
The exciter is a dual unit that produces sparks at each of the two igniter plugs. A continuous series of sparks is produced until the engine starts. The power is then cut off, and the plugs do not fire while the engine is operating other than on continuous ignition for certain flight conditions.
What is the purpose of an exciter unit?
The main purpose of exciter in a generator(alternator) is to provide stationary rotating magnetic field. Which is used to induce the e.m.f in the armature coil. So, DC power is given to exciter and the exciter is nothing but a coil, and the exciter creates a magnetic field.
What precautions should be taken with ignition systems and why?
Keep these 8 safety precautions in mind when working with ignition systems.
- Always wear OSHA-approved safety glasses when. …
- When working on any ignition system when the. …
- Never use your hands to pull high-tension wires. …
- When replacing parts or doing other work on the. …
- Always use the correct tools when working on.
How are turbine engine igniters operationally checked?
The igniter can be checked by listening for a snapping noise as the engine begins to turn, driven by the starter. The igniter can also be checked by removing it and activating the start cycle, noting the spark across the igniter.