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Frequency response of electrochemical sensors to hydrodynamic fluctuations

Published online by Cambridge University Press:  26 April 2006

C. Deslouis
Affiliation:
LP15 du CNRS Physique des Liquides et Electrochimie, Laboratoire de l'Université Pierre et Marie Curie. Tour 22, 4 place Jussieu, 75252 Paris Cedex 05, France
O. Gil
Affiliation:
LP15 du CNRS Physique des Liquides et Electrochimie, Laboratoire de l'Université Pierre et Marie Curie. Tour 22, 4 place Jussieu, 75252 Paris Cedex 05, France
B. Tribollet
Affiliation:
LP15 du CNRS Physique des Liquides et Electrochimie, Laboratoire de l'Université Pierre et Marie Curie. Tour 22, 4 place Jussieu, 75252 Paris Cedex 05, France

Abstract

The response of mass transfer to a small mass sink to hydrodynamic fluctuations in the concentration boundary layer has been calculated as a function of frequency. The dimensionless local flux was expressed as a series expansion of the dimensionless local diffusion layer thickness η and the dimensionless local characteristic frequency ξ in the low frequency range, and as the asymptotic power law $\xi^{-\frac{1}{3}}$, in the high frequency range. The two solutions were shown to overlap fairly well for 6 [les ] ξ [les ] 13. The overall transfer function over the whole mass sink area involves a spatial distribution for which the low-frequency approximation applies at the upstream end and the high-frequency approximation applies downstream. The average response at frequency f varies as f−1.

These theoretical predictions were tested electrochemically by using a rotating disk. The modulated limiting diffusion current due to a fast redox reaction at small circular microelectrodes embedded in the disk was measured as a function of the frequency of the modulation of the disk angular velocity.

Type
Research Article
Copyright
© 1990 Cambridge University Press

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References

Ambari, A., Deslouis, C. & Tribollet, B. 1986 Frequency response of the mass transfer rate in a modulated flow at electrochemical probes. Intl J. Heat Mass Transfer 29, 35.Google Scholar
Bogolyubov, Yu. Ye., Geshev, P. I., Nakoryakov, V. Y. & Ogorodnikov, I. A. 1972 Theory of electrodiffusion method applied to the characteristic spectra measurement in turbulent flow. Prikl. Mekh. Teckln. Fiz. 4, 112.Google Scholar
Cochran, W. G. 1934 The flow due to a rotating disk. Proc. Camb. Phil. Soc. 30, 365.Google Scholar
Deslouis, C., Epelboin, I., Gabrielli, C. & Tribollet, B. 1977 Impédance électromécanique obtenue au courant limite de diffusion à partir d'une modulation sinusoïdale de la vitesse de rotation d'une électrode à disque. J. Electroanal. Chem. 82, 251.CrossRefGoogle Scholar
Deslouis, C., Gabrielli, C., Sainte-Rose Fanchine, Ph. & Tribollet, B. 1982 Electrohydrodynamical impedance on a rotating disk electrode. I. Redox system. J. Electrochem. Soc. 129, 107.Google Scholar
Deslouis, C. & Tribollet, B. 1985 Mass transfer for a modulated flow at a rotating disk electrode; asymptotic solutions. J. Electroanal. Chem. 185, 171.Google Scholar
Deslouis, C., Tribollet, B. & Viet, L. 1983 The correlation between momentum and mass transfer for a turbulent or periodic flow in a circular pipe by electrochemical methods. 4th Intl Conference on Physicochemical Hydrodynamics, Ann. NY Acad. Sci. 404, 471.Google Scholar
Dumaine, J. Y. 1981 Etude numérique de la réponse en fréquence des sondes électrochimiques. Lett. Heat Mass Transfer 8 (4), 293.Google Scholar
Fortuna, G. & Hanratty, T. J. 1971 Frequency response of the boundary layer on wall transfer probes. Intl J. Heat Mass Transfer 14, 1499.Google Scholar
Kármán, Th. von 1921 Uber Laminare und turbulente Reibung. Z. angew. Math. Mech. 1, 233.Google Scholar
Leveque, M. A. 1928 Transmission de chaleur par convection. Ann. Mines 13, 283.Google Scholar
Ling, S. C. 1963 Heat transfer from a small isothermal span wise strip on an insulated boundary. Trans. ASME C: J. Heat Transfer 85, 230.Google Scholar
Mao, Z. X. & Hanratty, T. J. 1985 The use of scalar transport probes to measure wall shear stress in a flow with imposed oscillations. Expt Fluids 3, 129.Google Scholar
Mollet, L., Dumargue, P., Daguenet, M. & Bodiot, D. 1974 Calcul du flux limite de diffusion sur une microélectrode de section circulaire — Equivalence avec une électrode de section rectangulaire — Vérification expérimentale dans le cas du disque tournant en régime laminaire. Electrochimica Acta 19, 841.CrossRefGoogle Scholar
Nakoryakov, V. E., Budukov, A. P., Kashinsky, O. N. & Geshev, P. I. 1986 Electrodiffusion Method of Investigation into the Local Structure of Turbulent Flows (ed. V. G. Gasenko). Novosibirsk.
Nakoryakov, V. E., Kashinsky, O. N. & Kozmenko, B. K. 1983 Electrochemical method for measuring turbulent characteristics of gas—liquid flows. Measuring techniques in Gas—Liquid Two Phase Flows, IUTAM Symposium, Nancy, France, pp. 695721.
Newman, J. 1968 Numerical solution of coupled, ordinary, differential equations. Ind. Engng Chem. 7, 514.Google Scholar
Newman, J. 1973 Electrochemical Systems. Prentice Hall.
Patel, R. D., McFeely, J. J. & Jolls, K. R. 1975 Wall mass transfer in laminar pulsatile flow in a tube. AIChE J. 21, 259.Google Scholar
Pedley, T. J. 1972 On the forced heat transfer from a hot film embedded in the wall in two-dimensional unsteady flow. J. Fluid Mech. 55, 329.Google Scholar
Talbot, L. & Steinert, J. J. 1987 The frequency response of electrochemical wall shear probes in pulsatile flow. Trans. ASME K: J. Biomech. Engng 109, 60.Google Scholar
Tokuda, K., Bruckenstein, S. & Miller, B. 1975 The frequency response of limiting currents to sinusoidal speed modulation at a rotating disk electrode. J. Electrochem. Soc. 122, 1316.Google Scholar
Tribollet, B. & Newman, J. 1983 The modulated flow at a rotating disk electrode. J. Electrochem. Soc. 130, 2016.Google Scholar
Vorotyntsev, M. A., Martem'Yanov, S. A. & Grafov, B. M. 1984 Temporal correlation of current pulsations at one or several electrodes: A technique to study hydrodynamic fluctuation characteristics of a turbulent flow. J. Electroanal. Chem. 179, 1.Google Scholar