Combined heat and mass transfer along a vertical moving cylinder with a free stream

The mixed convection flow over a continuous moving vertical slender cylinde r under the combined buoyancy effect of thermal and mass diffusion has been studied. Both uniform wall temperature (concentration) and uniform heat (m ass) flux cases are included in the analysis. The problem is formulated in such a manner that when the ratio lambda(= u(w)/(u(w) + u(infinity)), where u(w) and u(infinity) are the wall and free stream velocities, is zero, the problem reduces to the flow over a stationary cylinder, and when lambda = 1 it reduces to the flow over a moving cylinder in an ambient fluid. The pa rtial differential equations governing the flow have been solved numericall y using an implicit finite-difference scheme. We have also obtained the sol ution using a perturbation technique with Shanks transformation. This trans formation has been used to increase the range of the validity of the soluti on. For some particular cases closed form solutions are obtained. The surfa ce skin friction, heat transfer and mass transfer increase with the buoyanc y forces. The buoyancy forces cause considerable overshoot in the velocity profiles. The Prandtl number and the Schmidt number strongly affect the sur face heat transfer and the mass transfer, respectively. The surface skin fr iction decreases as the relative velocity between the surface and free stre am decreases.