What is the function of a flywheel in machinery?

A flywheel serves a pivotal function in machinery by storing rotational energy and helping to stabilize speed fluctuations. When a machine operates, especially in environments with varying loads, the flywheel absorbs excess energy during periods of higher speed and releases it when the speed decreases. This capacity to store energy is crucial for ensuring a smooth and consistent operation of the machinery, as it mitigates the effect of sudden changes in load or speed.

The stabilization of speed fluctuations is important in applications where consistent performance is required, such as in engines or power generation systems. By maintaining a steady rotational speed, the flywheel contributes to overall efficiency and reduces wear and tear on moving parts, enhancing the machine's longevity and reliability.

Other options do not accurately describe the primary function of a flywheel. For instance, increasing friction would not be desirable in this context and could lead to inefficiencies. Similarly, while a flywheel may offer some vibration damping effects, its main function is not focused on reducing vibration. Finally, regulating coolant flow is unrelated to the flywheel's purpose, which centers primarily on energy storage and speed stabilization.