Sem título

Página 1

Heat Transfer:

Conduction, convection, Radiation.

Heat Radiation = transfer of heat by Infrared Radiation.

Conduction & Convection involve particles,

conduction is the main form of heat transfer in solids.

Convection is the main form of heat transfer in liquids and gases.

Infrared Radiation can be emitted by solids gases and liquids.

Any object can absorb/emit IR.

Bigger temp difference = faster energy transfer by heating.

IR:

All objects continually emitting and absorbing IR.

IR is emitted from the surface of an object.

Object hotter than surroundings = emits more radiation. Object cooler than surroundings = absorbs more radiation.

Hotter the object = more radiation radiated in a given time.

Surface Colour and Texture:

Dark, matte surfaces absorb IR better than light shiny surfaces. Dark, matte surfaces emit more IR