Convection Convection is the transfer of heat by the circulation of currents from a hotter to cooler...
-
Upload
amina-kille -
Category
Documents
-
view
216 -
download
0
Transcript of Convection Convection is the transfer of heat by the circulation of currents from a hotter to cooler...
Convection
• Convection is the transfer of heat by the circulation of currents from a hotter to cooler region.
• Convection currents only occur in liquids and gases because it involves movement of fluid particles.
• Convection is used in our daily lives as well as for natural things.
Convection
• Convection involves two processes: Diffusion and Advection• Diffusion is the random motion of the
individual particles in the fluid.• Advection is the transportation of heat by
the large-scale motion of currents in the fluid.
Convection
AdvectionDiffusion
Convection in liquid
Convection in gas• The smoke particles diffusing.
A B
A Smoke box
Sea Breeze in the day• Sea breeze is a wind from the sea caused by the movement of air particles.
The movement is caused by temperature differences between land and water.
Land breeze in the night
Oven• Forced convection is used in convection ovens
where fans circulate the hot air around the food
Rising of a hot-air balloon
Rising of gliders
Refrigerator
Ventilation of room
Boiling of water
Heating of water in a household water system
Home water heater system
Q1. Why does the foil spiral spin when the
flame is placed below it?
•When the cool air is warmed up by the flame, it rises, thus, the cool air rushes in underneath to fill the space and air currents are created. The currents make the convection curler turn.
Q2. Can convection take place in a solid?
•No, convection occurs in a environment such as air or liquid. Solids can only conduct heat.
Q3. Why are air conditioners not installed near the floor
of a room?
•The cold air from the air conditioner sinks, while the warm air, being lighter, rises to replace it. This creates a circulatory movement of air.
Done by:Claudia
Shireen