Dear crook,
How do I go about starting the problem?
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If you have been given the problem and the test rig to perform the
research. I would assume that the originator of the problem (I’ll call
them your supervisor) has a fairly well-defined idea of the problem,
the objectives and the expected solution mechanism. It would seem a
reasonable approach to take this research, together with the results
of some follow-up contacts and library research, write a short outline
and discuss it with your supervisor. An additional source of important
contacts would be those who have previously worked with your test rig…
presumably they would be a huge source of knowledge.
If your system is a simple horizontal or vertical pipe, it seems that
you may be able to apply Bakers mapping regime to characterize the
flow: stratified, slug, bubbles, annular, dispersed, wavy, foam etc
(Process Associates)
It seems that you then need parameters such as pressure, velocity,
surface tension, flow rate, viscosity and pipe characteristics to then
characterize the flow. The River City paper, solves for pressure drop
(whereas this is measured for your problem), but seems to outline a
reasonable calculation procedure for you to follow.
The University of Texas site seem very open to communication regarding
their project and I suspect a short email or telephone conversation
would be extremely helpful.
I have included a number of links for related studies, most seem to be
operating under special conditions: eg high temperatures, high flows,
but they do seem to make use of more sophisticated sensors such as
optical, electrical and even radioactive tracers. Perhaps these are
for your future research J
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This site has many photographs, movies and audio of two phase flow,
there is also an enquiry form and email address on the second page.
University of Texas, Visualization of Two Phase Fluid Flow in Pipes
http://socony.pe.utexas.edu/2phaseweb/
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Although this paper specifically deals with high velocity flow, it
contains a good overview of the current state of characterization of
two-phase flow. It also has an excellent list of references.
Edingfield, D. L., Evers, J., L., Techniques For The Measurement Of
The Air-Water Distribution
In The Flowfield Of A High Velocity Water Jet
http://www.wjta.org/Book%201/2_2a_Eddingfield_and_Evers.pdf
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Von Karmen Institute for Fluid Dynamics, Overview of applications:
http://www.vki.ac.be/research/themes/etpf99/3.html
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Process Associates have a number of useful tools
Two Phase Flow regime determination
http://www.processassociates.com/process/fluid/2faz_xy.htm
Two Phase Regime Map, very cool
http://www.processassociates.com/process/fluid/baker_h.htm
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Jehar and Associates provides a downloadable calculator based on Baker
flow regime maps
http://www.jehar.com/FreeProg.htm
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Scott S. Haraburda, Calculating Two-Phase Pressure Drop, There is also
a spreadsheet on the River City Engineering site.
http://www.rivercityeng.com/FFA2000-Calc2Phase.pdf
Are there related studies on the net?
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There are many, many investigations into two phase flow, but I could
not find any detailed papers that only relied on pressure sensors and
accelerometers.
Tulsa University description of Two Phase research site.
http://psc.tamu.edu/Research/Twoph.htm
Mary Kay O’Connor Process Safety Center, List of Papers on Two Phase
Flow
http://psc.tamu.edu/Research/Twoph.htm
C.E. Niederhaus and J.W. Jacobs, Richtmyer-Meshkov Instability shows
the use of accelerometers
http://info-center.ccit.arizona.edu/~fluidlab/papers/paper4.pdf
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Optical Methods:
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Dantec Dynamics, describes an optical method for characterizing flow:
http://www.dantecmt.com/piv/system/PIVPLIF/Index.html
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E. di Muoio et al, Optical Investigations Of Heii Two Phase Flow:
http://www.ujf-grenoble.fr/PHY/UFR/html/thibault/publi_thibault/Cec_difflumiere.pdf
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Ultrasonic sensors
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Robert A. Rabalais,”Ultrasonic Flow Measurement: Technology and
Application in Process and Multiple Vent Stream Situations,”
http://www.panametrics.com/div_rd/pdfs/UR234_Jan82002.pdf
http://mail.bris.ac.uk/~memag/Teaching/Multi/separated.pdf
Offline references
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Ultrasonic Characterization of Gas-Phase Systems
"Ultrasonic characterization of multiphase systems with gas as the
carrier phase has been accomplished at elevated pressure
(Chiang et al. 1994 and Bond et al. 1991) in the frequency range from
10 to 30 MHz. In gases, with lower wave velocity,
significant resolution is achievable at specific frequencies. At
atmospheric pressure, signal attenuation in gases is large
(Bond et al. 1992) and measurements are difficult to achieve.
Bond, L.J., C-H. Chiang, C.M. Fortunko, and J.D. McColskey. 1991. In
Proceedings IEEE Ultrasonics Symposium, p.1069-1073.
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Bond, L.J., C-H. Chiang, C.M. Fortunko. J. Acoust. Soc. Am. 1992, Vol.
92, p. 2006-2019.
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Chiang, C-H., L.J. Bond, W. Dube. In Proceedings Far East Conf. NDT
and 9 th ROCSNT. 1994, p. 449-456.
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Other Links:
Very cool thermodynamic calculator from San Diego University. It
doesn’t seem to handle two phase flow, but is very nice tool for
increasing understanding of flow.
http://thermal.sdsu.edu/testcenter/index.html
http://www.tanks.org/ttgdoc/PNNL-SA-32024.pdf
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Bakers Map from Caltech
http://www.cmp.caltech.edu/~mcc/Chaos_Course/Lesson5/Maps2D.pdf
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Strouhal and Weber Number derivation in Fay, James: Fluid Mechanics
Textbook
http://www.mas.ncl.ac.uk/~sbrooks/book/nish.mit.edu/2006/Textbook/Nodes/chap10/node10.html
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Search strategy:
characterizing OR characterising flow "two phase"
characterizing OR characterising flow "two phase" water accelerometer
pressure site:.edu
flow "two phase" water ultrasonic OR ultrasonics paper -oil
characterizing two phase flow pressure water –oil
fluid dynamics calculator "two phase" online
strouhal weber
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Wishing you all the best with your work.
Regards, |
