Advanced Laser Diagnostics for High Pressure Combustion
Student Intern: David Ruddock
SPARTAN ENGINEERING
Faculty Advisor: Dr. Tonghun Lee
Laser Diagnostics Laboratory for Energy & Environment Research
Department of Mechanical Engineering, Michigan State University
Laser Diagnostics Laboratory for Energy & Environment Research
Combustion · Advanced Energy Systems · Propulsion · Biofuels · Environment
Nitric Oxide, Oxygen and Carbon Dioxide Laser Induced Fluorescence Imaging
Laser Diagnostics Laboratory Research Focus
The goal is to develop advanced laser diagnostics for high pressure combustion (1-60 bar). Lasers can
provide selective and quantitative probing of chemical and physical parameters (i.e., temperature, species
concentration, etc.)
Research: Develop sensitive and robust laser imaging strategies for fundamental and practical
detection of chemical species and thermodynamic parameters
Upper Elec. State
A
Rotational Manifold
QVET
J’+2
J’+1
J’
J’-1
J’-2
v’=2
v’=1
v’=0
Q12
X
QRET
W12
W12
Laser Diagnostics Research
Energy Research
Development of 2D laser imaging
strategies for novel combustion
concepts and thermodynamic
parameters
Investigation of alternative energy
systems including hydrogen, novel
biofuels and energetic nanoparticle
additives
Propulsion Systems Research
Environment Research
Laser imaging of advanced propulsion
systems (automobile, aero and
astronautic propulsion systems)
Emission diagnostics. Real time
diagnostics of toxic chemicals and
multiphase particulate matter
V”=2
v”=1
v”=0
Planar Laser Induced Fluorescence (PLIF) results
Ground Elec. State
Laser Induced Fluorescence (LIF) Imaging
Molecules are excited to higher energy states
using narrow bandwidth laser energy. LIF is the
subsequent de-excitation to lower energy states
resulting in emission of fluorescence photons.
LIF can be used to image molecule
concentrations and temperature fields with 2D
resolution.
2D Temperature Imaging
Simultaneous Multiple Species Imaging
2x104ppm
High Pressure Burner
1bar =0.9
Pressure range (1-60 bar)
10bar =0.9
20bar =0.9
300K
40bar =0.9
60bar =0.9
2100K
Two-line and new multi-line thermometry
in collaboration with Stanford University, CA
O2
40bar =0.9
40bar =1.1
1x105ppm
Nitric Oxide (NO) Concentration Imaging
CO2
Issues with Elevated Pressure…
40bar =0.9
Collisional Broadening
Severe Attenuation of Laser and LIF
LIF of Multiple Species
Excitation lines of molecules are
collisionally broadened. Even with
narrow bandwidth lasers, multiples lines
can be excited. Overall signal is also
reduced.
Both the probe laser beam and the LIF
fluorescence signal can suffer from severe
attenuation by molecular absorption. In case
of UV light, hot CO2 is a strong absorber.
Spectrally resolved detection of the resulting
emission indicates that multiple species emit
LIF in the same spectral region. Therefore,
detection of single species can be altered by
interference from alternative signals.
NO
2000
1000
8
80
6
4
2
0
40
200
0
225.86
225.88
225.90
225.92
225.94
225
250
275
10bar =0.9
20bar =0.9
40bar =0.9
60bar =0.9
1bar =1.1
10bar =1.1
20bar=1.1
40bar =1.1
60bar =1.1
80
235.87 nm ex
60
Data
NO
O
40
2
Rayleigh
CO
20
2
Total
0
Emission Wavelength [nm]
Spectrally resolved emission using UV excitation
40bar =1.1
Practical Applications
20bar =0.9
40bar =0.9
60bar =0.9
10bar =0.9
20bar=0.9
40bar =0.9
60bar =0.9
0ppm
Application in practical high pressure
combustion systems
• Design Optimization
• Combustion Study
• Pollution Control
10bar =0.9
9104ppm
Novel CO2 sensor using UV excitation/detection
20bar=1.1
0ppm
Simultaneous Imaging of O2 and CO2 using multi-spectral LIF
New multi-spectral Imaging for isolation of NO signal
300
Absorption cross sections of CO2
500ppm
UV Carbon Dioxide (CO2) Concentration Imaging
220 230 240 250 260 270 280 290 300
Wavelength [nm]
Excitation lines of NO
1bar =0.9
0ppm
B=242.14nm A=239.23nm
LIF Intensity [a.u.]
120
3000
Emission Signal [a.u.]
CO2
4000
1bar
30bar
0ppm
20bar =0.9