Laser Induced Incandescence Diagnostic For Soot Measurements
Faculty Advisors
Dr. Pham1
Professor Dunn-Rankin2
Student Assistants
Michael Tran2
10/1/2009 NASA Grant URC NCC NNX08BA44A 1
1) California State University, Los Angeles, CA 90023
2) University of California, Irvine, CA 92697
PRESENTATION OUTLINE
• Soot Background• Diagnostic Techniques• Laser Induced Incandescence (LII)• My Research• Future Work
NASA Grant URC NCC NNX08BA44A 210/1/2009
3NASA Grant URC NCC NNX08BA44A
SOOT BACKGROUND
• Soot- Carbonaceous solid particles due to incomplete combustion
• Main constituents are carbon (97-99%%) and hydrogen (1-3%) by wt.
Individual Soot Particles 10-50nm
Soot Aggregates
Transmission Electron Microscopy (TEM)- Lund University)
10/1/2009
4NASA Grant URC NCC NNX08BA44A
Environmental and health aspects of soot• Contributes to 25% of global warming• Climate change• Particles < 1 micron can enter
human respiratory system
Benefits in soot• Carbon Black
• Tire industry• Ink
Air Pollution in Los Angeles, Time Magazine
SOOT BACKGROUND
10/1/2009
5NASA Grant URC NCC NNX08BA44A
DIAGNOSTIC TECHNIQUES
Probe techniques• Gravimetric Sampling• Disadvantage: Intrusive,
limited in spatial resolution and temporal response
Laser Diagnostics• Laser Induced Incandescence• Advantage: Non-intrusive• Disadvantage: Optical access
and expensive
Sampling Technique, Florida International University LIIScience.org
10/1/2009
6NASA Grant URC NCC NNX08BA44A
LASER INDUCED INCANDESCENCE
• Goal: Qualitative and quantitative measurement of soot• Output: Soot profile, soot volume fractions, and particle size• Principle:
– Soot is heated by laser (3500-4000K)– Incandescence flame images soot profile– Incandescence intensity soot volume fraction– Temporal decay of incandescence particle size
Laser Induced Incandescence, Lund University
10/1/2009
7NASA Grant URC NCC NNX08BA44A
LII THEORY
Lund University
10/1/2009
8NASA Grant URC NCC NNX08BA44A
TYPICAL LII COMPONENTS
Laser• UV to visible light (532nm) to IR
(1064nm)
Detector• ICCD Camera• Photomultiplier Tube
Soot Generator • Flame• Engine• Combustor
Lund University
Trigger Mechanism
• Function generator
Filter
• Filter range 300-600nm (400nm preferred)
10/1/2009
9NASA Grant URC NCC NNX08BA44A
MY RESEARCH
Goal• Compare sooting characteristics of neat and various blends of biodiesel to
diesel fuel in a diffusion candle flame and counter flow flame using Laser Induced Incandescence
10/1/2009
10NASA Grant URC NCC NNX08BA44A
EXPERIMENTAL SET UP
A
B C
D
E
F
G
H
I
J
K
A 532 Nd:Yag Laser
B Mechanical Iris
C/D Beam Steering Optic
E/F Cylindrical Lens
G Candle Flame
H 532nm Nd:Yag Dielectric Mirror
I 320nm Band-pass Filter
J ICCD Camera
K Beam Stopper
Photodiode (Not Labeled)
10/1/2009
11NASA Grant URC NCC NNX08BA44A
EXPERIMENTAL SET UP
Camera Control Unit
Oscilloscope
Function Generator
ICCD Camera
Photodiode
10/1/2009
12NASA Grant URC NCC NNX08BA44A
RESULTS AND ANALYSIS
Iso-octane Diesel Biodiesel
Flame images captured by hand-held digital camera
10/1/2009
13NASA Grant URC NCC NNX08BA44A
RESULTS AND ANALYSIS
Flame image of iso-octane captured by ICCD camera (No laser)
Laser induced incandescence of iso-octane captured by ICCD camera
Iso-octane Iso-octane
10/1/2009
14NASA Grant URC NCC NNX08BA44A
RESULTS AND ANALYSIS
Laser induced-incandescence images captured by ICCD camera
Iso-octane Diesel Biodiesel
10/1/2009
15NASA Grant URC NCC NNX08BA44A
RESULTS AND ANALYSIS
Flame intensity profile (incandescence)
Laser Induced incandescence profile
Note: Intensity not scaled
Iso-octane Iso-octane Diesel Bio-diesel
10/1/2009
16NASA Grant URC NCC NNX08BA44A
RESULTS AND ANALYSIS
Normalized intensity contour plot
Iso-octane Iso-octane Diesel Biodiesel (incandescence) (induced incandescence) (induced incandescence) (induced incandescence)
10/1/2009
FUTURE WORK
• Collect data holding constant flame height• Obtain quantitative measurement (soot volume fraction and particle size distributions)• Compare soot formation in diffusion candle flame versus counter flow flame
NASA Grant URC NCC NNX08BA44A 1710/1/2009
ACKNOWLEDGMENTS
• Grant provide by NASA # NNX08BA44A• Lasers, Flames, Aerosols Laboratory, UCI• Space Center, CSLA
NASA Grant URC NCC NNX08BA44A 1810/1/2009
QUESTIONS
NASA Grant URC NCC NNX08BA44A 1910/1/2009