LIQUID FUELS AND SPRAYS
Plain Jet in Crossflow
OVERVIEW
As environmental emissions considerations become more
important in the development or upgrade of systems, the
generation and control of the fuel spray plays an increasingly
significant role. One reason for this is that the emissions
of pollutants in exhaust streams is a function of the spray
quality irrespective of the actual combustion system used.
This research is aimed at gaining a better understanding
of the characteristics of sprays generated by injecting
liquid fuel jets into a cross flow of air as might be found
in the premixing duct of a gas turbine fuel injector.
OBJECTIVES
- Collect data on for the jet produced by a “recessed” liquid
jet injector using high speed videography for a distillate
fuel under elevated pressure and temperature conditions.
- Establish
a correlation describing the penetration and behavior
of the jet and examine the sensitivity of the
results to the analysis protocols and assumptions
made regarding velocities
- Compare the current results to existing correlations
based on flush wall jet configurations
RESULTS
Ambient temperatures and pressures between 350 and 475
K and 3.7 to 6.4 atm were considered for a range of liquid
flow rates. High speed, short exposure digital shadowgraphy
was utilized to document the behavior. Instantaneous images
were extracted, averaged, and analyzed to provide data
on penetration vs. downstream distance.
The test section is a straight 2-D duct. A liquid jet
is formed by passing fuel through an orifice located in
one wall of the test section. The wall jet is a plain orifice,
having an L/D of 5. The orifice is located at the entrance
to a short tube, which shields the jet as it passes through
the test section wall.
Conclusions:
- Low momentum flux cases (q < 30) were isolated and
a regression analysis carried out. The best correlation
coefficients were obtained with the following
formulation:
- At higher momentum flux ratios, two of the more recently
developed penetration correlations appear to provide
a better description.
- Inclusion of dimensionless parameters such as the
Weber number and viscosity ratio improves the range of
momentum
flux ratios that can be predicted.
Data Comparison for New Low Momentum
Correlation (q<30)
Data comparison Including Webber
Number and Viscosity (q<75)
RECENT PUBLICATIONS/PAPERS
SOME OBSERVATIONS OF LIQUID
JETS IN CROSSFLOW (2005). Proceedings,
18th ILASS-Americas Conference, Irvine, CA (B.J. Masuda,
R.L. Hack, V.G. McDonell, G. Oskam, and D. Cramb).
PERSONNEL
Undergraduate Students: Brandon J. Masuda
Staff: Richard L. Hack
Investigators: Prof. G.S. Samuelsen and Dr. V.G. McDonell
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