Analysis of laminar forced convection with Network Simulation in thermal entrance region of ducts

The transient heat transfer problem referring to a fully laminar flow developing in pipes exposed to a step change in the temperature is studied here. Bi-dimensional (axial-radial) wall and fluid heat conduction are assumed. The effects of pipe thickness, Peclet number, wall-to-fluid conductivity ratio and thermal diffusivity ratio are determined in the solutions. Boundary condition other than isothermal may easily be incorporated in the model with no special requirements. The numerical procedure employed permits the solution for both transient and steady-state problems at the same time, and its programming does not require manipulation of the sophisticated mathematical software that is inherent in other numerical methods. The network simulation method, which satisfies the conservation law for the heat flux variable and the uniqueness law for temperature, also permits the direct visualisation and evolution of the local and/or integrated transport variables at any point or section of the medium. (C) 2003 Elsevier SAS. All rights reserved.