Investigation to Extend the Applicability of Laser Raman Scattering Diagnostic Techniques to Practical Combustion Systems.
Abstract
Laser Raman scattering diagnostic techniques may be precluded from application to practical combustion devices due to a variety of laser-particulate (soot) interaction 'noise' effects. Under the subject contract the laser particulate interaction has been studied in some detail. Laser induced particulate temperatures have been measured as a function of laser flux and are found to agree fairly well with an analytical model. The scaling of the absolute noise has been studied and the noise has been found to saturate with increasing laser energy and decrease with decreasing focal length lenses. The effect of signal averaging pulsed Raman data obtained in an unsteady medium has been analyzed. Averaged Raman data is shown to depend not only on average temperature but on the magnitudes and correlations of medium fluctuations in density and temperature. Noise sampling and subtraction have been shown to be feasible and a temperature measurement demonstration was performed on a soot seeded laboratory burner using the above approach. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 13, 1976
- Accession Number
- ADA032493
Entities
People
- Alan C. Eckbreth
Organizations
- Purdue University