Heat Conduction Through Composite Cylindrical Walls

Note The terms contained in braces are associated with viscous dissipation and may usually be neglected, except for systems with large velocity gradients. 

By writing an energy balance for the solid over a differential volume element 27rrArL, we get 

The heat flux at the inner wall can be expressed in terms of an overall heat transfer coefficient as 

Uo is defined as the overall heat-transfer coefficient based on the inside area. 

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Figure 6.5 Heat Conduction Through Composite Cylindrical Walls.

We are interested in computing the steady-state heat flux for conduction through composite material cylindrical walls. A diagram of the system is given in Figure 6.5. 

Figure 8.1. Temperature profiles in one-dimensional conduction of heat, (a) Constant cross section, (b) Hollow cylinder, (c) Composite flat wall, (d) Composite hollow cylindrical wall, (e) From fluid A to fluid F through a wall and fouling resistance in the presence of eddies, (f) Through equivalent fluid films, fouling resistances, and metal wall.

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