Statistics – Applications
Scientific paper
Sep 2000
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000phdt........47d&link_type=abstract
Thesis (PhD). UNIVERSITY OF COLORADO AT BOULDER, Source DAI-B 61/07, p. 3801, Jan 2001, 192 pages.
Statistics
Applications
Scientific paper
The combustion of magnesium in oxygen and carbon dioxide has been known for some time and is of significant interest for fire safety, solid propellant applications, and, recently, for use as an in-situ resource propellant of planetary exploration of Mars. Detailed knowledge of the fundamental combustion processes in magnesium combustion is lacking, in part because of difficulties in experimental measurements and numerical modeling caused by high heat release and solid products. In this work a Laser Induced Fluorescence technique has been developed to probe magnesium oxide in the reaction zone of bulk samples of magnesium burning in atmospheres of oxygen and carbon dioxide. In support of this work, fluorescence excitation scans of the MgO A 1Π-B1Σ+ transition have been performed in a magnesium-chloride seeded acetylene-air flame. This spectroscopic study expands the data available for this electronic transition, in particular at high rotational states. A large number of rotational and vibrational transitions are observed in the seeded flame with a significant amount of overlapping. A rotational analysis of the v = 0 and 2 bands of the B1Σ + state has been completed. The analysis of the v = 2 B1Σ + state is the first since the original analysis from 1949. MgO PLIF imaging during the combustion of bulk magnesium has shown several differences between reaction in oxygen as compared to carbon dioxide. Combustion in oxygen shows quasi-steady behavior while combustion in carbon dioxide demonstrates pulsatory behavior. Ample evidence is found to suggest that a reaction-inhibiting carbon containing layer forms during heating in carbon dioxide. Combustion of 4-mm diameter and height cylinders in 21% O2 balance Ar at 1 atm, on a flat surface in gravity, produces a broad gas phase reaction zone, which encompasses the entire melted disk (6-mm radii) and extends above the disk to two disk radii. Analysis of laser scatter imaging and comparison to a control volume model suggests that product particles rapidly form to a size less than 100 nm to 300 nm. Analysis of MgO PLIF imaging produces a measurement of the peak A1Π state population at 1.715 × 10 21 m-3 when burning in oxygen, while when burning in carbon dioxide, the analysis predicts the population to be 6.65 × 1019 m-3. Assuming a thermal electronic distribution, the total MgO population during combustion in O2 is in reasonable agreement with thermodynamic equilibrium calculations assuming stoichiometric reactants and adiabatic reaction, while in CO2 the measured population is significantly smaller. This work is the first application of laser diagnostic techniques to the study of magnesium combustion. Two laser based diagnostics have been developed: a laser scatter technique and a PLIF technique for magnesium oxide imaging. The limitations of the techniques have been quantified and applications of the techniques have been demonstrated.
No associations
LandOfFree
Laser induced fluorescence imaging of magnesium oxide during the combustion of magnesium in oxidizing atmospheres does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Laser induced fluorescence imaging of magnesium oxide during the combustion of magnesium in oxidizing atmospheres, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Laser induced fluorescence imaging of magnesium oxide during the combustion of magnesium in oxidizing atmospheres will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-764605