CONDUCTION THROUGH A CYLINDRICAL WALL

TermsInside radius=r1, outside radius = r2T inside = Ts1, T outside = Ts2Length L

Assumptionsone dimension / without generation / steady stateGeneral Heat Equation Cylindrical Coordinates: One Dimension / Without Generation / Steady State

if Integrating

= C1 .... (i)T=C1 log r + C2 (ii)Boundary conditionsT= Ts1 at r=r1 AND T=Ts2 at r=r2

TEMPERATURE DISTRIBUTIONApplying boundary conditions and solving

HEAT FLOW

qr= - kA = -k (2rL)

=

loge = Ts2 - Ts1

Or q = (2kL) =

Where Rt =

** Temperature distribution is logarithmic not linear as in plane walls: but almost linear if

qr= - kAmean = q = (2kL)

Amean =

rmean =