Final answer:
The flywheel on a piston engine smooths out engine vibrations by increasing angular momentum, providing stability and a more consistent engine output.
Step-by-step explanation:
Conventional piston engines utilize flywheels to smooth out engine vibrations caused by individual piston firings. This smoothing effect occurs because the flywheel, due to its mass and radius, has a significant moment of inertia which allows it to store rotational kinetic energy. As individual pistons fire, they impart pulses of energy that lead to rotational acceleration of the engine's crankshaft. The flywheel resists these rapid speed changes due to its stored kinetic energy, which is related to its angular momentum. This resistance increases angular momentum, thus dampening the abrupt changes in speed and smoothing out the overall rotation of the engine. In this way, the flywheel provides a stabilizing influence, ensuring a more consistent engine output with less perceptible vibration.