On the hydrodynamics turbulent control of mass transfer in electrodeposition process

A wall-slit jet serves as a mean of hydrodynamics control for turbulence of an electrolyte flow in a backstep channel equipped with electrochemical cells to improve mass transfer of an electrodeposition process. Experimental and computational works were done to elucidate the effect of flow parameters to the rate of mass transfer between cell electrodes. The solution of CuSO ₄ of 0.5 M was used as electrolyte fluid. The rate of mass transfer was determined by measuring the local limiting current at mini cathodes placed in the electrochemical cell. Some results showed that the wall-slit jet altered the flow structure and turbulence intensity. The reattachment point shifted to upstream position, the recirculation zone reduced in size meanwhile the turbulence intensity increased. These flow characteristics altered the rate of convective ionic mass transfer. Within the range of Reynolds number 1500 < Re < 4800 and velocity ratio of 0.7 < V _r < 2.6 it is found the mass transfer relation can be presented a non-dimensional equation of Sh = 0.033Re ^0.598Sc ^0.33, where Sh is the Sherwood number and Sc is the Schmidt number of the flow.