posted on 2018-08-15, 08:11authored byDonald H. Barnhart
This thesis reports on the development of two, conceptually different, holographic measurement
systems for the study of three-dimensional displacement and velocity fields. The first approach
reported in this thesis is an intensity correlation-based holographic velocimetry system that employs a
reference-multiplexed, off-axis geometry for determining velocity directions using the cross-correlation
technique, and a stereo camera geometry for determining three-dimensional fluid velocity fields.
The pulsed-laser recording system produces three-dimensional particle images with resolution, signal-to-
noise ratio, accuracy and derived velocity fields that are comparable to high-quality two-dimensional
photographic PIV (particle image velocimetry). The high image resolution is accomplished by
using low f-number optics, a fringe-stabilized processing chemistry, and a phase conjugate play-back
geometry that compensates for aberrations in the imaging system. This holographic velocimetry system
is then used to successfully measure the volumetric, three-dimensional velocity field of an air nozzle
jet flow. In this experiment, more than five million three-dimensional velocity vectors are successfully
identified within a single hologram result. [Continues.]
Funding
EPSRC (grant no.: GR/K11147). Royal Society, R.W. Paul Instrument Fund. Rover Group plc.
History
School
Mechanical, Electrical and Manufacturing Engineering
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2001
Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy at Loughborough University.