This work describes a method for determining a three-dimensional velocity
profile of a flow through a micro geometry. The aim of this thesis is to
further develop a micro-PIV method previously used to measure displacements
and deformations in a plane. Micro-PIV methods are not a in it self a new
method in this sorts of applications, on the contrary, it is a well known
and documented method for measuring and calculating velocities and
deformations in micro scales. The recent progress in micro-technology pushes
the development of measuring techniques adapted for micro-geometries
forward. The method that is developed in this thesis is not interesting
entirely for scientists but also for companies in areas such as wood fiber
products, polymer composites, micro fluidics and biomaterial. The unique in
this method is to show that the technique can be used to measure a tree-
dimensional velocity profile.
The method that this work is based on has been developed at Luleå University
of Technology. The earlier method is based on correlation calculation
between images that has been taken with a CCD-camera, parted with a time
interval. The achieving goal with PIV-methods is to compare the intensity
between these images, and in that way find the displacements on the
specimen. The development in this thesis is to gather data from layers
through a capillary tube. The gathered information is then put together, and
this gives a picture of the flow through the geometry in a three-dimensional
perspective. The head alignment in this work has been to find a qualitative
picture of the three-dimensional velocity profile. The trail setup does not
allow any quantitative validation of the velocities. Therefore has the
concentration in the work been to find a method with potential for future
development, that measures the shape of the velocity profile in a truthfully
way. The method that has been developed in this work and that is built on
the earlier PIV-method is developed in the mathematic program Matlab. This
program is suitable for the calculations and visualizations that are
required. A future step in development of this method is to rewrite the
Matlab codes in C-code for increased speed in the calculations.
The future development of the technique that is presented in this thesis
should include measurements in more complicated geometries such as
constrictions or bent capillary tubes. Future development could also include
transient flows or real time measurements of micro flows. The measurements
that has been done in this work has been done on Newtonian flows, where the
measured velocities easily can be verified against known theories. An area
that this method can be used in the future is flow measurements on non...
