Mass transfer investigation in turbulent flow downstream of sudden enlargement of a circular pipe for very high schmidt numbers

Abstract This paper reports the results of an experimental investigation, which employs the technique of “Diffusion-Controlled Electrolysis”, for the determination of mass-transfer rates in the separated and redeveloping regions downstream of a sudden enlargement of a circular pipe. The data are presented for Schmidt number of 1400 and 2500 and for Reynolds number ranging between 2500 and 89000. The results are compared with some other existing data and it is concluded that the mass-transfer behaviour is strongly influenced by the boundary conditions but its dependence on Schmidt number is rather weak. Finally it is shown that the reattachment-zone mass-transfer rates show a simple power-law dependence on the Reynolds number.