There are three modes of heat transfer mainly conduction heat transfer,convection heat transfer and radiation heat transfer.But some authors and professors believe that there are only 2 modes of heat transfer mainly :-Conduction and Radiation.They believe Convection heat transfer is simply "Conduction" through the boundary layer.
Is it correct to bring convection under the purview of conduction heat transfer?
Thanks!!
What I had inferred from many papers is that CONVECTION = ADVECTION + DIFFUSION.
ADVECTION - transporting some quantity or material via bulk motion, by the fluid. eg., transport of pollutants or silt in a river by bulk water flow
DIFFUSION - transfer of heat through molecules and in turn to the neighboring medium.
Hence if we take an example of hot plate surrounded by layer of bulk fluid particles near surface of plate, the heat gets transferred from plate to fluid is by CONDUCTION first followed by DIFFUSION, then by ADVECTION and at last by CONVECTION.
Hence the one that links CONDUCTION and CONVECTION appears to be ADVECTION.
This is why we use PRANDTL NUMBER which relates the viscous diffusion of liquid to thermal diffusion by solids, as part of Convection Heat Transfer.
Convective heat transfer occur when heat is transmitted from one location to another by the movement of fluids. Basically fluid carries energy as it moves, usually from a high temperature location to a low temperature location. Moreover, note that there exist different regions within thermal boundary layer namely, region near the surface where molecular diffusion (conduction) dominant over eddy thermal diffusion, molecular thermal diffusion (conduction) and eddy thermal diffusion all are equal, equal and lastly region by which the eddy thermal diffusion becomes dominant over molecular diffusion (conduction). This indicates that the modes of energy transfer (conduction and convection) normally occur simultaneously or rather intertwined. However, the significance of these modes depends on the problems at hand, which means the LESS SIGNIFICANT mode is oftentimes neglected.
hello susheel..
what do you mean by "CONDUCTION first followed by DIFFUSION, then by ADVECTION and at last by CONVECTION"??
Convection is a combination of diffusion and advection so as u said convection will follow advection is actually not correct!
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