What is the primary function of a flywheel in an engine?

The primary function of a flywheel in an engine is to store rotational energy. Flywheels are designed to maintain a steady speed by storing energy in the form of kinetic energy as they spin. When the engine generates power, the flywheel absorbs some of that energy during the power stroke and releases it during the non-power strokes, ensuring smoother operation and reducing fluctuations in engine speed. This energy storage capability helps to moderate the power supply from the engine, enabling it to run more efficiently and reducing the chances of stall during operation.

In contrast, the other options do not accurately describe the function of a flywheel. For example, while increased speed can be beneficial, the flywheel itself does not inherently increase the speed of the engine; rather, it stabilizes rotational energy. Additionally, flywheels do not convert electrical energy, as that function is more closely related to generators and alternators. Finally, while flywheels may help minimize engine noise to some extent, their primary purpose is not noise reduction but rather the storage of rotational energy to enhance smoothness and efficiency in engine performance.