Conjugate Film Flow Down a Heated Vertical Wall

Abstract

The conjugate flow of a film down a heated vertical wall of finite length is investigated theoretically. It is shown that the momentum boundary‐layer equation leads to an exact solution for the velocity field, but the energy equation is nonsimilar. Solutions of this nonsimilar equation, subject to appropriate boundary conditions, are obtained numerically using an efficient finite‐difference scheme. Series solutions which are valid near the leading edge of the wall and far downstream are also obtained and compared with the corresponding numerical solutions. The distribution of the surface wall temperature and in the film region are also determined for values of the Prandtl number of 0.6 (air) and 6.7 (water).