Jet Engine Data Analysis - University of California,...
Transcript of Jet Engine Data Analysis - University of California,...
Jet Engine Data Analysis
DARPA-funded experiments at United Technologies Research Center Hartford ConnecticutJet engine combustion instability - also occurs in turbomachinery
Thermo-acoustic instability; a periodic self-sustained oscillationInteraction between heat release rate and acoustics
Results in engine “Hooting” or “Howling” - audible toneOccurs at low equivalence (fuel-to-air) ratio !
Low ! is good for pollution - low NOx - and maintenanceHooting destroys the benefits
Periodically very high then very low temperaturesDescribe this mathematically using a model
Then look for a control approach1
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Single-nozzle rigone combustor from a ring
measure pressuremeasure heat release rate
5,000 Hz sampling
Experimental Set-up
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Theory - Rayleigh 1877Experiment - Rijke Tube 1859
- bunsen burner in an open tube with a wire gauze mesh
Heat into sound
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0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36 0.38 0.4−8
−6
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Time (s)
Pres
sure
(uni
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Pressure signal
0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36 0.38 0.40
0.2
0.4
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Time (s)H
eat r
elea
se ra
te (u
nits
)
Heat release rate signal
Experimental Data
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Data - pressure, log heat release rate
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0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36 0.38 0.4−15
−10
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Time (s)
Pres
sure
(uni
ts),
Log
heat
rele
ase
rate
(uni
ts)
Signals
Saturday, 5 November, 2011