LOW PECLET NUMBER HEAT TRANSFER IN A LAMINAR TUBE FLOW SUBJECTED TO AXIALLY VARYING WALL HEAT FLUX.

An analytical solution technique suitable for handling low Peclet number forced convection heat transfer problems in conduits subjected to axially varying heat flux at the conduit wall is presented. A new super-position principle is used to deal with the effects of axial conduction. Results are presented for several different wall heat flux distributions, including sinusoidal and hyperbolic tangent type profiles. Hyperbolic tangent profiles will better approximate conduction through tube walls than discontinuous flux distributions used in previous analyses. Results show that axial conduction effects are important not only near the inlet to a heated section, but also in any part of the heated section where the wall flux varies rapidly with axial position.