Final answer:
Ignition in a piston engine occurs intermittently and uses a flywheel to smooth out vibrations from individual explosions, while a turbine engine has continuous combustion and does not require a flywheel.
Step-by-step explanation:
The main difference between the ignition systems on a piston engine versus a turbine engine lies in the method and frequency of ignition. In a piston engine, as part of the four-stroke cycle, the air-fuel mixture is ignited once per cycle via spark plugs, causing an explosion that pushes the piston down. This motion is translated into rotational motion by the crankshaft, and a flywheel is used to smooth out engine vibrations caused by the thrust of individual piston firings. The flywheel has this effect due to its ability to store rotational energy, providing a damping effect that reduces the impact of the power strokes' uneven force distribution.
In contrast, a turbine engine, which is designed for rapid and continuous spinning, ignites the air-fuel mixture in a continual, controlled burn rather than through intermittent explosions. This creates a steady stream of high-pressure gas that turns the turbine blades, generating thrust or mechanical power. Jet turbine engines lack the need for a flywheel because their operation is inherently smoother due to the continuous combustion process.