Heat Transfer Flashcards
What causes the movement of fluid in convection?
Temperature differences within the fluid cause density differences, leading to the movement of warmer, less dense fluid rising and cooler, denser fluid sinking.
How does convection occur in the atmosphere?
The sun heats the Earth’s surface, causing the air close to the ground to warm up and rise, while cooler air from higher altitudes descends, creating wind and weather patterns.
What is forced convection?
Forced convection occurs when external forces, such as fans or pumps, move the fluid. An example is a fan blowing air over a hot radiator.
What is natural convection?
Natural convection occurs due to natural density differences without external forces. An example is warm air rising and cool air sinking in the atmosphere.
What is conduction?
Conduction is the transfer of heat through a material by direct contact of its particles.
How does conduction work?
In conduction, heat is transferred when particles in a material gain kinetic energy and vibrate, colliding with neighboring particles and transferring energy from the hot region to the cold region.
Why are metals good conductors of heat?
Metals are good conductors of heat because they have free electrons that move easily and transfer energy quickly.
Why are non metals poor conductors of heat?
Non - Metals are poor conductors of heat because they have no free electrons that move easily and transfer energy quickly.
How does the temperature difference affect conduction?
The greater the temperature difference between the hot and cold ends, the faster the heat conduction.
What is the role of cross-sectional area in conduction?
A larger cross-sectional area allows more heat to be conducted and allows conduction to occur quicker.
How does the length of a material affect heat conduction?
The shorter the distance the heat has to travel, the faster the conduction.
If you want to prevent heat in your house.
What type of materials would you build with.
Insulating Materials. They would help to keep the warm air out by not allowing it to flow through.
If you want to make a cable for a charger. What type of materials would you use
Conducting Materials. Due to the presence of free electrons, electricity would flow through easily.
Repeated convection is known as
A convection current
What is convection?
Convection is the transfer of heat by the movement of a fluid (liquid or gas) caused by temperature differences within the fluid.
