Convection

Definition

Convection is the transfer of heat through the movement of fluids (liquids or gases) caused by temperature differences. It involves the physical motion of the fluid, carrying energy from one place to another.

5 Must Know Facts For Your Next Test

1. Convection can be natural or forced. Natural convection occurs due to buoyancy effects, while forced convection involves external forces like fans or pumps.
2. The rate of convective heat transfer can be described by Newton's Law of Cooling: $Q = hA\Delta T$, where $Q$ is the heat transfer rate, $h$ is the convective heat transfer coefficient, $A$ is the surface area, and $\Delta T$ is the temperature difference.
3. In Earth's atmosphere, convection currents are responsible for weather patterns and phenomena such as wind and storms.
4. Convective heat transfer plays a crucial role in many engineering applications including heating and cooling systems, automotive engines, and even in biological systems like blood circulation.
5. Laminar and turbulent flow are two types of fluid flow affecting convection. Laminar flow has smooth streamlines while turbulent flow has chaotic eddies.

Review Questions

• What is the main difference between natural convection and forced convection?
• How does Newton's Law of Cooling relate to convective heat transfer?
• Why are laminar and turbulent flows important when studying convection?

Related terms

Conduction:

The process by which heat energy is transmitted through collisions between neighboring atoms or molecules without any motion of the material as a whole.

Radiation:

The transfer of energy by electromagnetic waves; it does not require a medium to travel through.

Buoyancy: A force exerted by a fluid that opposes an object's weight; it drives natural convection currents within fluids.