  A theoretical study is presented in this paper to investigate the conjugate
heat transfer across a vertical finite wall separating two forced and free
convection flows at different temperatures. The heat conduction in the wall is
in the transversal direction and countercurrent boundary layers are formed on
the both sides of the wall. The governing equations of this problem and their
corresponding boundary conditions are all cast into a dimensionless form by
using a non-similarity transformation. These resultant equations with multiple
singular points are solved numerically using a very efficient singular
perturbation method. The effects of the resistance parameters and Prandtl
numbers on heat transfer characteristics are investigated.
