A fast response method for detection of ignition and extinction of liquid spray flames has been improved. Also, a method of determining fuel-to-air ratios and temperatures of pre-mixed, gaseous flames has been developed. Both methods utilize chemiluminescent signals from an OH system centered at 309 nm and a CH system centered at 431 nm. The ignition and extinction method was improved by replacing an optical system composed of lenses and a monochromator by a system composed of a fiber optic cable and band pass interference filters. The use of a solid-state photodiode instead of a photomultiplier tube was investigated. Transient histories of the OH and CH signals were recorded by performing light-off ignition and intermittent ignition flame tests. These signal histories were compared to histories obtained using the original apparatus. The fuel-to-air ratio and temperature detection method was investigated by recording the spectra of laminar, pre-mixed methane flames of known stoichiometry with a lens, monochromator, and photomultiplier tube set-up and measuring the flame temperatures with a high-temperature Pt-10%Rh thermocouple. Various combinations of signal characteristics were found to be functions of fuel-to-air ratio and temperature. Optimum signals for monitoring with a detector were determined. Recommendations for future work in this area are discussed. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/42410 |
| Date | 02 May 2009 |
| Creators | Johnsson, Erik L. |
| Contributors | Mechanical Engineering, Roby, Richard J., O'Brien, Walter F. Jr., Roe, Larry A. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis, Text |
| Format | x, 124 leaves, BTD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | OCLC# 23810460, LD5655.V855_1991.J656.pdf |
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