Eur. Phys. J. E (2012) 35: 62
https://doi.org/10.1140/epje/i2012-12062-5

Regular Article

Near-field laser Doppler velocimetry measures near-wall velocities

¹ Foundation for Research and Technology Hellas, IESL, 71110, Heraklion, Greece
² Forschungszentrum Jülich, ICS-3, 52425, Jülich, Germany

^* e-mail: benoit@iesl.forth.gr

Received: 19 August 2011
Revised: 30 March 2012
Accepted: 20 June 2012
Published online: 23 July 2012

Abstract

A new near-wall velocimetry technique is proposed, based on evanescent wave dynamic light scattering, which allows for the measurement of near-wall velocity profile (characterized by an apparent slip velocity and a shear rate) with a resolution of tens of nanometers. A full theoretical expression of the correlation function is derived for the case of linear flow with negligible Brownian motion. The technique is demonstrated for latex spheres dispersed in water-glycerol mixtures.