Simulation of Turbulent Flow of a Rotating Cylinder Electrode. Influence of Using Plates and Concentric Cylinder as Counter Electrodes
ABSTRACT This paper focuses on the effect of plates and a concentric cylinder used as counter electrodes on the turbulent flow of a rotating cylinder electrode (RCE). Four-plate, six-plate, and concentric cylinder counter electrodes were simulated. A 3-D hydrodynamic simulation was performed solving the Reynolds averaged Navier-Stokes (RANS) equation, expressed in terms of turbulent viscosity and the standard turbulence model k–ε, with the universal logarithmic wall function boundary conditions. The results of the velocity field 3-D simulations clearly show the formation of turbulent Taylor vortex flow for the four-plate and six-plate arrangements, while in the concentric arrangement, it does not appear. The appearance of Taylor vortex is attributed to the turbulence promoted by the plates. However, this does not imply that the mean velocity profile is favored by the plates; on the contrary, these plates promote the formation of quasi stagnant zones near to them and on the wall of the reactor free of plates. The above findings are important, from the technical and economical standpoints, in the design of this type of electrochemical cell; additionally, such systematic hydrodynamic studies in these cells are rather limited.