Coupled forced convection heat and mass transfer in a circular tube with external convective heating

Coupled heat and mass transfer in a circular tube with a slug flow inside and external convective heating was solved analytically. The closed form solutions of temperature and concentration profiles, Nusselt and Sherwood numbers were obtained. The results show that the Nusselt number, based on heat transferred to the fluid inside the tube, is identical to the Sherwood number when the Lewis number is unity. The effect of the Biot number on heat and mass transfer was also investigated.