Heat transfer that occurs through physical contact between two fluids is known as?

The process of heat transfer that takes place through physical contact between two fluids is termed conduction. This method occurs when two substances at different temperatures are in contact, allowing thermal energy to transfer from the hotter substance to the cooler one until thermal equilibrium is reached. In the case of fluids, when they come into direct contact, the faster-moving molecules of the hotter fluid collide with the slower-moving molecules of the cooler fluid, transferring energy in the process.

Other heat transfer mechanisms, such as convection, involve the bulk movement of fluid and would not apply strictly to situations of direct contact. Radiation, on the other hand, entails heat transfer through electromagnetic waves and does not require physical contact between the objects. Diffusion generally refers to the movement of particles from areas of high concentration to areas of low concentration, which is not specifically related to heat transfer in the same sense as conduction. Thus, conduction is distinct as it specifically involves the direct transfer of heat through contact between fluids.