Experimental And Numerical Analysis Of Channel Flow For Use As Electrochemical Reactor

Elsevier Editorial System(tm) for Experimental Thermal and Fluid Science Manuscript Draft Manuscript Number: Title: Experimental and numerical analysis of channel flow for use as electrochemical reactor Article Type: Research Paper Keywords: PIV, CFD, electrochemical reactor, channel flow, turbulence modeling Corresponding Author: Mr. Fernando Z Sierra, Ph.D. Corresponding Author's Institution:Universidad Autonoma del Estado de Morelos First Author: Fernando Z Sierra, Ph.D. Order of Authors: Fernando Z Sierra, Ph.D.; Gustavo Rodriguez, B.Sc.; Leticia Vazquez, Ph.D.; Candelario Bolaina, M.Sc. Abstract: The flow dynamics in a parallel plate channel with divergent inlet and convergent outlet is experimentally and numerically investigated. The RANS analysis is conducted by comparing thesolution of three models for turbulence: k-e, RNG and RSM. A water flow condition proper for electrochemical applications with a Reynolds number, Rei = 2500, based on the average velocity and the diameter at the inlet section of the channel, was considered. The parallel plates of the channel are 10 mm apart from each other to form a confined domain with symmetry axis along the streamwise flowdirection and diverging-converging angles of 19.3o/30.3o, respectively. The channel is evaluated as an electrochemical reactor since its geometry corresponds to that of a commercial prototype. The inlet section before the divergence aligns with the main flow direction, while the outlet located after the convergent section is oriented at right angle. This arrangement produces a complex vortex activity farfrom a well ordered fully developed flow, which is desired for a uniform electrochemical reaction in terms of mass transport that is used to measure the performance of the reactor. The three models were invoked to solve the problem in 3-D and steady state. Since this Rei approximates to transition to turbulence, the presence of vortex structures represents a challenge for any turbulence model inorder to reproduce the velocity field characteristics. A good agreement was observed between the solution obtained with the RNG model and the experiment. It is observed that the velocity gradients emerge asymmetrically as a combination of effects of geometry at both inlet and outlet. The divergent section perturbs the flow and leads to a recirculation flow region that reduces the effective crosssection area of mass flow and affects the mass transport, which was confirmed using particle image velocimetry, PIV. Suggested Reviewers: Frank C. Walsh Ph.D Professor, School of Engineering Science, University of Southampton F.C.Walsh@soton.ac.uk Dr. Walsh is an expert in electrochemical reactors. Jose C Texeira Ph.D. Professor, Mechanical Engineering, University do Minho d228@dem.uminho.pt Dr.Texeira is an expert in fluid dynamics.

Opposed Reviewers:

Cover Letter

F. Z. Sierra-Espinosa Centro de Investigación en Ingeniería y Ciencias Aplicadas, CIICAp Universidad Autónoma del Estado de Morelos, UAEM Av. Universidad 1001, Chamilpa, Cuernavaca, Morelos, 62209 MEXICO Phone: (777) 329 70 84 ext. 6210 October 5, 2006. Dr. G.P. Celata
Institute of Thermal Fluid Dynamics, ENEA, ViaAngulillsrese 301 Santa Maria di Galeria, 00123 Rome, Italy, Email: celata@enea.it

REF.: Experimental and numerical analysis of channel flow for use
as electrochemical reactor By G. Rodríguez, L. Vázquez, C. Bolaina, F. Z. Sierra*, A. Álvarez
Dear Dr. Celata: Please find enclosed an original paper, which we submit for publication in the Experimental Thermal and Fluid Science Journal. We hopeyou find this paper suitable for publication in the above-mentioned Journal. Looking forward to hearing from you, receive my best regards. Sincerely

Fernando Z Sierra
fse@uaem.mx

CIICAp-UAEM

*Manuscript Click here to view linked References

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