Fundamental Studies of Soot Formation and Diagnostic Development in Nonpremixed Combustion Environments
Anthony Bennett, Ph.D. Candidate Supervised by Professor William Roberts
Thursday, June 25, 2020
04:00 PM - 05:00 PM
Soot from combustion emissions has a negative impact on human health and the environment. Understanding and controlling soot formation is desirable to reduce this negative impact, especially as energy demands continue to increase. In this work, a range of fundamental combustion experiments are performed to better understand the soot formation process, and to develop diagnostics for measuring soot properties.
First, studies on the effects of ammonia addition, a possible future fuel, on soot formation in laminar non-premixed ethylene counterflow flames was performed. A reduction in soot volume fraction was observed and attributed to chemical effects of ammonia addition. Second, an investigation and development of soot diagnostics was performed. Differences between reported soot scaling factors of soot with pressure were explored. Time resolved laser induced incandescence (TiRe-LII), a diagnostic for measuring particle sizes was advanced by investigating the effects of soot volume on the local gas heating. Finally, the application of TiRe-LII in pressurized environments was assessed using laminar coflow flames. Comparisons between TiRe-LII and thermophoretically captured soot imaged by transmission electron microscopy (TEM) was performed. TiRe-LII was found to have reasonable agreement with TEM measurements if the signal to noise ratio was high, but due to the large disparity in primary particle size in pressurized environments errors in 2D TiRe-LII can be significant.