Which process primarily involves the transfer of heat through a fluid?

The process that primarily involves the transfer of heat through a fluid is convection. This phenomenon occurs when warmer areas of a fluid (which can be a liquid or gas) rise, while cooler areas sink, creating a cyclical movement that results in the transfer of heat. As the fluid moves, it carries heat energy with it, allowing for effective distribution of thermal energy throughout the fluid.

In contrast, conduction is the transfer of heat through direct contact between materials, while radiation refers to the transfer of energy through electromagnetic waves, which can occur in a vacuum as well as in various media. Evaporation involves the transformation of liquid into vapor, where thermal energy is absorbed by the liquid molecules but is not a process focused on the transfer of heat through a fluid.