Definition Of Convection

Convection implies the form of heat transfer, by real movement of matter, that occurs only in fluids. Fluid alludes to any substance, whose molecules move freely from one place to another, such as liquid and gases. It happens naturally or even forcefully.

Gravity has a great role to play in natural convection such that when the substance is heated from below, leads to the expansion of the hoter part. Due to buoyancy, the hotter substance rises as it is less dense and the colder substance replaces it by sinking at the bottom, due to high density, which when gets h0t moves upward, and the process continues. In convection, on heating up the substance, it’s molecules disperse and moves apart.

When the convection is performed forcefully, the substance is compelled to move upwards by any physical means such as the pump. E.g. Air heating system.