Fluid flow effects on diffusion layer and current density for electrochemical systems
- PDF / 730,650 Bytes
- 13 Pages / 595 x 842 pts (A4) Page_size
- 103 Downloads / 146 Views
pISSN: 0256-1115 eISSN: 1975-7220
INVITED REVIEW PAPER
INVITED REVIEW PAPER
Fluid flow effects on diffusion layer and current density for electrochemical systems Behzad Ebadi*,**, Morteza Behbahani-Nejad*,**,†, Maziar Changizian*,**, and Ioan Pop*** *Department of Mechanical Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, 61357-83151, Ahvaz, Iran **Gas Networks Research Center, Shahid Chamran University of Ahvaz, 61357-83151, Ahvaz, Iran ***Department of Mathematics, Faculty of Mathematics and Computer Science, Babeş-Bolyai University, 400084 Cluj-Napoca, Romania (Received 14 November 2019 • Revised 12 March 2020 • Accepted 12 April 2020)
AbstractThe effects of flow field upon the distribution of ionic concentration, electric potential, concentration boundary layer thickness, and electric current density were investigated. A modified numerical scheme is proposed to simulate the corresponding electrochemical system which is governed by nonlinear partial differential equations. Seven types of geometries and various flow fields with Reynolds numbers up to 2100 are considered. The obtained results indicate the current numerical method can successfully simulate the increase of current density on the cathode as the applied potential cell increases, and that rise will continue until the limiting current density is reached. To predict the effect of fluid flow, the proposed scheme is applied for various Peclet numbers. The increase of current density for Peclet numbers between 1 and 104 is quite evident. But for large Peclet numbers between 104 and 107, the current density increases gradually. The results also show that as the anode size is doubled, the maximum current density occurs at the leading and trailing edges. However, if the cathode size is doubled, the maximum current density occurs at the center regions of it. Knowing the regions where current density is extremum helps electochemical system designers to control the parameters of the corresponding process. Keywords: Non-linear Coupled Manner, Electrochemical Systems, Diffusion Layer, Butler-Volmer, Fluid Flow
diffusion and migration [6,7]. In some electrochemical applications, the convection term can be overlooked due to the static nature of electrolyte. However, in the majority of applications, the convection term should be underscored due to the presence of appreciable fluid flow. For instance, the cathodic protection systems of ships moving through the sea water are influenced by forced convection [8]. As an additional example, batteries could be affected through the free convection being formed with concentration gradient on the electrodes realm [9]. The numerical solving of electrochemical equations, in the general form without any simplification, is very cumbersome due to nonlinearity of both the governing equations and the Butler-Volmer boundary condition on electrodes. Moreover, electrochemical applications are typically faced with high Peclet numbers, applying serious convergence difficulties in the electrochemistry modellin
Data Loading...
