3 edition of Using laser-induced incandescence to measure soot/smoke concentrations found in the catalog.
Using laser-induced incandescence to measure soot/smoke concentrations
by National Aeronautics and Space Administration, Lewis Research Center, National Technical Information Service, distributor in Cleveland, Ohio, Springfield, VA
Written in English
|Other titles||Using laser induced incandescence to measure soot/smoke concentrations.|
|Statement||Randall L. Vander Wal.|
|Series||[NASA contractor report] -- NASA/CR-97-206325., NASA contractor report -- NASA CR-206325.|
|Contributions||Lewis Research Center., United States. National Aeronautics and Space Administration.|
|The Physical Object|
A calibration-independent laser-induced incandescence technique for soot measurement by detecting absolute light intensity David R. Snelling, Gregory J. Smallwood, Fengshan Liu, Ömer L. Gülder, and William D. Bachalo Laser-induced incandescence (LII) has proved to be a useful diagnostic tool for spatially and temporally. In this study, the system is used for laser-induced incandescence measurements to obtain quantitative 3-D soot volume fraction distributions in both .
Some methods to quantify the soot concentration by Laser-Induced Incandescence were developed using a flat flame burner in our previous work [ 1 ]. Those methods take the following points into consideration. (1)a correction of the LII signal intensity profile distorted by the laser atte. The excitation of the soot particles by laser-induced incandescence is typically performed with pulsed laser radiation, e.g. Nd:YAG with pulse duration of 10 ns at fundamental laser wavelength nm with laser fluence ∼ J/cm 2 or frequency-doubled nm at ∼ J/cm 2. The basic optical arrangement of LII setup is shown in Figure 2.
Fourier transform IR (FTIR) spectroscopy for making non- intrusive measurements of gas turbine exhaust gases and laser induced incandescence for measuring soot content are being evaluated in EU Brite EuRam project AEROJET. Soot concentrations in modern aero-engine exhausts are very low with mean particle sizes. time of soot level have been measured by the laser-induced incandescence (4). In Figure 12 the filtered data from selected downslope (fall time) peak of soot emission normalised to % are shown.
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Pulsed laser diagnostics (1). Only recently have researchers demonstrated that this laser-induced emission can be used as a measure of the soot concentration (), thereby validating theoretical predictions (). In accord with the Planck radiation law, soot’s radiative emission at these elevated temperatures increases in intensity and shifts toCited by: 4.
Get this from a library. Using laser-induced incandescence to measure soot/smoke concentrations. [Randall L Vander Wal; Lewis Research Center.]. With this technique, soot was heated to the sublimation point by the laser pulse, causing increased incandescence.
The LII signal was imaged with an ICCD camera 20 ns after the laser pulse to avoid. 1Laser induced incandescence for soot measurements in technical flames at increased pressure at the ONERA M1 test rig: Niveau: Supérieur, Master, Bac+41Laser-induced incandescence for soot measurements in technical flames at increased pressure at the ONERA M1 test rig Klaus Peter Geigle1, Jochen Zerbs1, Christian Guin2 1Institute of Combustion Technology, DLR, Pfaffenwaldring.
Abstract: The laser-induced incandescence (LII) technique has emerged as a viable non-intrusive technique for measuring soot concentration in flames. The incandescence of soot occurs when laser light heats the particles to the incandescent temperature (which is typically /spl sim/4, K).
Laser-induced incandescence (LII) measurement is an emerging technology that promises to be a reliable means for spatially and temporally measuring the soot volume fraction and primary soot particle size.
Eckbreth () recognized the concept while working with Raman spectroscopy in flames and was troubled by the presence of soot. Laser‐induced incandescence (LII) is introduced as a valuable tool for the characterization of nanoparticles. This optical measurement technique is based on the heating of the particles by a short laser pulse and the subsequent detection of the thermal radiation.
Abstract “The laser-induced incandescence (LII) signal is proportional to soot volume fraction” is an often used statement in scientific papers, and it has – within experimental uncertainties – been validated in comparisons with other diagnostic techniques in several investigations.
Incandes- cence of soot occurs when laser light heats the soot particles to near its vaporization tempera- ture (typically ~ K). It has been predicted that the resulting radiant emission intensity is proportional to the soot concentration .
Roi and Zak live inside the Splinter, a world of rock that swims in a sea of light they call the Incandescence. Living on the margins of a rigidly organised society, they seek to decipher the subtle clues that can reveal the true nature of the Splinter. In this paper, the sooting propensity of various blends of soybean biodiesel and Ultra Low Sulfur Diesel (ULSD) fuels are investigated using both a traditional ASTM D standard smoke lamp and modern Laser-Induced Incandescence (LII) technique.
Laser excitation is achieved using a pulsed Nd: YAG laser operating at nm wavelength. Laser-induced incandescence (LII) is a widely used technique for measuring soot concentrations.
For flame applications LII is frequently deployed as a. Laser-induced incandescence (LII) is a widely used technique for measuring soot concentrations. For flame applications LII is frequently deployed as a planar diagnostic to measure the two-dimensional soot field.
However, when the laser sheet is focused, as is typical to reach the requisite laser fluence level and achieve good spatial resolution, the complex laser power dependence of the. Using a fixed flame height, laser-based measurements are generally consistent with smoke point trends, and laser extinction calibrations provide quantitative soot volume fractions.
The results show the greatest soot concentration for pure diesel fuel, B0, and the least for a 20% blend by volume of biofuel, B A novel technique for two-dimensional measurements of soot volume fraction and particle size has been developed.
It is based on a combined measurement of extinction and laser-induced incandescence using Nd:YAG laser wavelengths of nm and nm. Abstract. Laser-Induced Incandescence (LII) occurs when a high-energy pulsed laser is used to heat soot to incandescent temperatures. Theoretical calculations predict and experimental tests demonstrate the resulting incandescence to be a measure of soot-volume fraction.
Laser-induced incandescence (LII) is a technique based on detection of light emitted from heavily heated soot particles. Soot absorbs radiation very effectively and behaves similar to black body radiators. This is the reason why soot is very common as pigment. Laser induced incandescence (LII) is an in-situ non-intrusive diagnostic which allows studying soot format as well as soot concentration measurements In.
Measurements of soot volume fraction in pulsed diffusion flame by laser induced incandescence 24 August | Experiments in Fluids, Vol. 44, No. 1 2D soot volume fraction imaging in an ethylene diffusion flame by two-color laser-induced incandescence (2C-LII) technique and comparison with results from other optical diagnostics.
() On the dependence of the laser-induced incandescence (LII) signal on soot volume fraction for variations in particle size.
Applied Physics BOnline publication date: 1-Jan. Laser-induced incandescence and light scattering have been proven to measure the primary soot particle size as well in atmospheric flames; however, using these two techniques for the purpose of primary soot particle sizing in diffusion flames .Laser-induced incandescence (LII) is an established and widely-used technique for measuring soot particle size and concentration .
The technique involves using a high power pulse laser to heat soot particles to near-sublimation temperature, causing the heated particles to emit broadband radiation that can be detected as a raw LII signal .This proposal describes the development of a system to measure in-situ and in real-time, the size distribution and mass concentration of soot particles in turbojet exhausts.