Convection Heat Transfer and Radiation

convection healtransfer OThe method of heat trans- - per from one past of the body to other by the act- ual movement of particles. 1 During convection the densi- ty of molecules decreases then they rises Up. eg : sea breeze, land Greeze , t- raole breeze, boilingwatter. from Game hear Radiation O it is the mode of heat tran- sfer in the form of electron- agnetic radiations. It doesn't require any m edium. 1 It travells through vaccum

with a speed of light (3x10 m/s). Oil is the fastest mode of heat transfer. Qincident Preferred Qabso abed Gransmitted Pincident = Pref + Prant Q abs Absorptive power (a); a= a assorbed Pinciaen Reflectivity (r) r= Preflected Qincident Transmittivity (t) t = Qtransmitted incident at +++ =1 pure absorber a=1 r=t =0

Pure affector i 0=1 a=t=0 pure transmitted; t=1 a=d=0