Conditions for similitude between the fluid velocity and electric field in electroosmotic flow
Abstract
Electroosmotic flow is fluid motion driven by an electric field acting on the net fluid charge produced by charge separation at a fluidsolid interface. Under many conditions of practical interest, the resulting fluid velocity is proportional to the local electric field, and the constant of proportionality is everywhere the same. Here the authors show that the main conditions necessary for this similitude are a steady electric field, uniform fluid and electric properties, an electric Debye layer that is thin compared to any physical dimension, and fluid velocities on all inlet and outlet boundaries that satisfy the HelmholtzSmoluchowski relation normally applicable to fluidsolid boundaries. Under these conditions, the velocity field can be determined directly from the Laplace equation governing the electric potential, without solving either the continuity or momentum equations. Three important consequences of these conditions are that the fluid motion is everywhere irrotational, that fluid velocities in twodimensional channels bounded by parallel planes are independent of the channel depth, and that such flows exhibit no dependence on the Reynolds number.
 Authors:
 Publication Date:
 Research Org.:
 Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
 Sponsoring Org.:
 US Department of Energy (US)
 OSTI Identifier:
 751024
 Report Number(s):
 SAND998246
TRN: AH200019%%15
 DOE Contract Number:
 AC0494AL85000
 Resource Type:
 Technical Report
 Resource Relation:
 Other Information: PBD: 1 Apr 1999
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; OSMOSIS; ELECTRIC FIELDS; FLUID FLOW; FLOW RATE; ELECTRIC POTENTIAL; FLOW MODELS
Citation Formats
E. B. Cummings, S. K. Griffiths, R. H. Nilson, and P. H. Paul. Conditions for similitude between the fluid velocity and electric field in electroosmotic flow. United States: N. p., 1999.
Web. doi:10.2172/751024.
E. B. Cummings, S. K. Griffiths, R. H. Nilson, & P. H. Paul. Conditions for similitude between the fluid velocity and electric field in electroosmotic flow. United States. doi:10.2172/751024.
E. B. Cummings, S. K. Griffiths, R. H. Nilson, and P. H. Paul. Thu .
"Conditions for similitude between the fluid velocity and electric field in electroosmotic flow". United States.
doi:10.2172/751024. https://www.osti.gov/servlets/purl/751024.
@article{osti_751024,
title = {Conditions for similitude between the fluid velocity and electric field in electroosmotic flow},
author = {E. B. Cummings and S. K. Griffiths and R. H. Nilson and P. H. Paul},
abstractNote = {Electroosmotic flow is fluid motion driven by an electric field acting on the net fluid charge produced by charge separation at a fluidsolid interface. Under many conditions of practical interest, the resulting fluid velocity is proportional to the local electric field, and the constant of proportionality is everywhere the same. Here the authors show that the main conditions necessary for this similitude are a steady electric field, uniform fluid and electric properties, an electric Debye layer that is thin compared to any physical dimension, and fluid velocities on all inlet and outlet boundaries that satisfy the HelmholtzSmoluchowski relation normally applicable to fluidsolid boundaries. Under these conditions, the velocity field can be determined directly from the Laplace equation governing the electric potential, without solving either the continuity or momentum equations. Three important consequences of these conditions are that the fluid motion is everywhere irrotational, that fluid velocities in twodimensional channels bounded by parallel planes are independent of the channel depth, and that such flows exhibit no dependence on the Reynolds number.},
doi = {10.2172/751024},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Apr 01 00:00:00 EST 1999},
month = {Thu Apr 01 00:00:00 EST 1999}
}

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