Effect of Uniform Suction on Laminar Film Condensation on a Porous Vertical Wall

The problem of film condensation on a porous wall has been solved by a boundary layer treatment. A dimensionless suction velocity parameter β, which is proportional to the uniform suction velocity vw and 1/4th the power of longitudinal coordinate (x1/4), is defined to characterize the process. The results are restricted to small values of β, as the solutions are given by power series expansion in β. The effects of uniform suction on heat transfer, condensation rate, film thickness, and velocity and temperature profiles are demonstrated through various examples. In general, uniform suction causes a substantial increase of heat transfer and condensation rate, especially at low subcooling and at high Prandtl numbers. The problem involves three governing parameters: subcooling, Prandtl number, and suction velocity. Comparison with the previous work of Jain and Bankoff is discussed.