What are two types of convection?

Answer 1

Convection is broadly the movement of any molecules through any fluid state, including liquids and gasses. It is the primary form of heat and mass transfer on Earth, and can be found in many systems around the world. Many people are familiar with convection from heating their food or their houses, and it also plays a pivotal role in creating the weather conditions on the planet.

There are two main types of convection: forced convection and natural convection.

Natural convection occurs when the medium transferring the heat is being inspired to move by the heat itself. This happens both because the medium expands as it heats up, as in the case of gases, and also because buoyancy causes the warmer fluid to rise. Natural convection is also sometimes referred to as free convection. The two types of convection, forced and natural, often occur at the same time, where the heat is causing the fluid to move somewhat, but it is also moving because of some other force. In this case, it is referred to as mixed convection.

Forced convection can be seen in many places in the world, both in man-made objects and in the natural world. For example, a convection oven forces heated air to circulate through the oven by using a fan. Although the air might move somewhat on its own, the forced convection allows for an even disbursement of heat. Within the human body, the circulatory system is another great example of forced convection. Blood, among its many other uses, acts as both a heating agent and cooling agent for the body, and is forced through the circulatory system.