What defines forced convection?

Forced convection is defined as the process in which fluid movement is driven by an external force, typically through mechanical means like fans or pumps. This external force causes the fluid to flow over a surface or through a medium, enhancing heat transfer rates compared to natural convection, where fluid motion arises from temperature differences alone.

In forced convection, as the fluid is forced to flow, it can carry heat away from surfaces more efficiently. For example, when air is blown over hot surfaces using a fan, the air's movement improves heat dissipation. This concept is critical in many engineering applications, such as heating and cooling systems, where enhancing heat transfer is essential for performance and energy efficiency.

Understanding that forced convection relies on external mechanisms for fluid movement distinguishes it from natural convection, where circulation occurs solely due to buoyancy effects arising from temperature differences within the fluid.