Multilayer nano-particle image velocimetry

Multilayer nano-particle image velocimetry Nano-particle image velocimetry (nPIV), based on evanescent-wave illumination of fluorescent colloidal tracers, measures the two velocity components parallel to the wall averaged over the first few hundred nanometers next to the wall. The intensity of the evanescent wave decays exponentially with z, or the distance normal to the wall. Illuminated tracers closer to the wall therefore have images that are brighter than those farther from the wall. This nonuniform illumination presents the possibility to extend the technique to “multilayer nPIV,” where the two velocity components parallel to the wall can be estimated at different z-locations within the illuminated region. In this paper, the variation of tracer image intensity with distance from the wall was predicted using diffraction optics-based approaches. The predictions, which were validated by calibration experiments, show that particle image intensity decays exponentially with distance normal to the wall. The feasibility of multilayer nPIV was evaluated using artificial images of plane Couette flow that incorporate evanescent-wave illumination, hindered Brownian diffusion and image noise. Each image was divided into three sub-images based on tracer image intensity, and standard techniques were then used to extract temporally and spatially averaged velocities at three different z-locations. In these simulations, velocity data were obtained within 80 nm of the wall, a threefold improvement over previous measurements. The results demonstrate that multilayer nPIV is feasible if appropriate classification techniques are developed and used to separate tracer images into different layers. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Experiments in Fluids Springer Journals

Multilayer nano-particle image velocimetry

Loading next page...
 
/lp/springer_journal/multilayer-nano-particle-image-velocimetry-gU0pnyTJMg
Publisher
Springer-Verlag
Copyright
Copyright © 2006 by Springer-Verlag
Subject
Engineering; Engineering Fluid Dynamics; Fluid- and Aerodynamics; Engineering Thermodynamics, Heat and Mass Transfer
ISSN
0723-4864
eISSN
1432-1114
D.O.I.
10.1007/s00348-006-0155-4
Publisher site
See Article on Publisher Site

Abstract

Nano-particle image velocimetry (nPIV), based on evanescent-wave illumination of fluorescent colloidal tracers, measures the two velocity components parallel to the wall averaged over the first few hundred nanometers next to the wall. The intensity of the evanescent wave decays exponentially with z, or the distance normal to the wall. Illuminated tracers closer to the wall therefore have images that are brighter than those farther from the wall. This nonuniform illumination presents the possibility to extend the technique to “multilayer nPIV,” where the two velocity components parallel to the wall can be estimated at different z-locations within the illuminated region. In this paper, the variation of tracer image intensity with distance from the wall was predicted using diffraction optics-based approaches. The predictions, which were validated by calibration experiments, show that particle image intensity decays exponentially with distance normal to the wall. The feasibility of multilayer nPIV was evaluated using artificial images of plane Couette flow that incorporate evanescent-wave illumination, hindered Brownian diffusion and image noise. Each image was divided into three sub-images based on tracer image intensity, and standard techniques were then used to extract temporally and spatially averaged velocities at three different z-locations. In these simulations, velocity data were obtained within 80 nm of the wall, a threefold improvement over previous measurements. The results demonstrate that multilayer nPIV is feasible if appropriate classification techniques are developed and used to separate tracer images into different layers.

Journal

Experiments in FluidsSpringer Journals

Published: May 30, 2006

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off