TY - JOUR
T1 - Spatially resolved measurements of soot volume fraction using laser-induced incandescence
AU - Quay, B.
AU - Lee, T. W.
AU - Ni, T.
AU - Santoro, R. J.
N1 - Funding Information:
This material is based upon work supported by the Air Force Office of Scientific Research under Award No. F49620-92-J-0314 with Dr. Julian Tishkoff as contract manager and their support is gratefully acknowledged. The authors would also like to thank J. A. Pinson and S. Gupta of Penn State for many useful discussions and J. E. Harrington, C. R. Shaddix, and K. C. Smyth of the National Institute of Standards and Technology for providing us with their results on the effects of laser fluence on LH signals. We would also like to acknowledge the reviewers for their suggestions regarding the light scattering anabysis and the effects of aggregates on the interpretation of the results of this work.
PY - 1994/6
Y1 - 1994/6
N2 - Laser-induced incandescence is used to obtain spatially resolved measurements of soot volume fraction in a laminar diffusion flame, in which comparisons with laser scattering/extinction data yield excellent agreement. In addition, the laser-induced incandescence signal is observed to involve a rapid rise in intensity followed by a relatively long (ca. 600 ns) decay period subsequent to the laser pulse, while the effect of laser fluence is manifest in nonlinear and near-saturated response of the laser-induced incandescence signal with the transition occurring at a laser fluence of approximately 1.2 × 108 W/cm2. Spectral response of the laser-induced incandescence involves a continuous spectrum in the visible wavelength range due to the blackbody nature of the emission. Simultaneous measurements of laser-induced incandescence and light scattering yield encouraging results concerning the mean soot particle diameter and number concentration. Thus, laser-induced incandescence can be used as an instantaneous, spatially resolved diagnostic of soot volume fraction without the need for the conventional line-of-sight laser extinction method, while potential applications in two-dimensional imaging and simultaneous measurements of laser-induced incandescence and light-scattering to generate a complete soot property characterization are significant.
AB - Laser-induced incandescence is used to obtain spatially resolved measurements of soot volume fraction in a laminar diffusion flame, in which comparisons with laser scattering/extinction data yield excellent agreement. In addition, the laser-induced incandescence signal is observed to involve a rapid rise in intensity followed by a relatively long (ca. 600 ns) decay period subsequent to the laser pulse, while the effect of laser fluence is manifest in nonlinear and near-saturated response of the laser-induced incandescence signal with the transition occurring at a laser fluence of approximately 1.2 × 108 W/cm2. Spectral response of the laser-induced incandescence involves a continuous spectrum in the visible wavelength range due to the blackbody nature of the emission. Simultaneous measurements of laser-induced incandescence and light scattering yield encouraging results concerning the mean soot particle diameter and number concentration. Thus, laser-induced incandescence can be used as an instantaneous, spatially resolved diagnostic of soot volume fraction without the need for the conventional line-of-sight laser extinction method, while potential applications in two-dimensional imaging and simultaneous measurements of laser-induced incandescence and light-scattering to generate a complete soot property characterization are significant.
UR - http://www.scopus.com/inward/record.url?scp=0028457182&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028457182&partnerID=8YFLogxK
U2 - 10.1016/0010-2180(94)90029-9
DO - 10.1016/0010-2180(94)90029-9
M3 - Article
AN - SCOPUS:0028457182
SN - 0010-2180
VL - 97
SP - 384
EP - 392
JO - Combustion and Flame
JF - Combustion and Flame
IS - 3-4
ER -