TY - CONF
T1 - Reduction of flame development time using nanosecond-Pulsed high-Frequency discharges in flowing mixtures
AU - Lefkowitz, Joseph K.
AU - Ombrello, Timothy
N1 - Funding Information: This study explored the effects of inter-pulse time and number of pulses on the flame development rate. The major conclusions are that increasing inter-pulse time (decreasing PRF) results in faster kernel growth rate for constant total energy deposition, as long as the kernel is in the fully-coupled regime. This means that lower power deposition is actually optimal for flame growth rate, which is the opposite trend from what was found for ignition probability [3]. Increasing the number of pulses (i.e., total energy deposition) reduced ignition development time at a fixed inter-pulse time. However, this effect is only fully realized for relatively long inter-pulse times, which are able to take advantage of the fluid motion to expand the ignition kernel. 5. Acknowledgements This research was funded by the NRC under the Research Associateship Program. 6. References [1] Y. Ju, W. Sun, Plasma assisted combustion: Dynamics and chemistry, Prog. Energy Combust. Sci. 48 (2015) 21–83. [2] D.R. Ballal, A.H. Lefebvre, The influence of flow parameters on minimum ignition energy and quenching distance, Symp. (Int.) Combust. 15 (1975) 1473–1481. [3] J.K. Lefkowitz, T. Ombrello, An exploration of inter-pulse coupling in nanosecond pulsed high frequency discharge ignition, Combust. Flame (2017), submitted. [4] J. Canny, A computational approach to edge detection, IEEE T. Pattern Anal. 6 (1986) 679-698. [5] R. Halır, J. Flusser, Numerically stable direct least squares fitting of ellipses, Proc. 6th International Conference in Central Europe on Computer Graphics and Visualization 98 (1998) 125-132. Publisher Copyright: © 2017 Eastern States Section of the Combustion Institute. All rights reserved.
PY - 2017
Y1 - 2017
N2 - This study explores the flame development rate of ignition kernels initiated by nanosecond-pulsed high-frequency discharges in a flowing methane/air mixture at an equivalence ratio of 0.6, velocity of 10 m/s, and pressure of 101 kPa. Both the pulse repetition frequency (PRF) and the number of pulses were varied in the range of 10 – 300 kHz and 1 – 50 pulses (≈ 3 – 150 mJ), respectively, to study the effects of power deposition rate and total energy deposition on the flame development rate. It was found that lowering the PRF increased the flame development rate, as long as the ignition kernel had high probability for success. It was also found that greater numbers of pulses increased the flame development rate, but was much more effective at 10 kHz PRF as compared to 300 kHz PRF.
AB - This study explores the flame development rate of ignition kernels initiated by nanosecond-pulsed high-frequency discharges in a flowing methane/air mixture at an equivalence ratio of 0.6, velocity of 10 m/s, and pressure of 101 kPa. Both the pulse repetition frequency (PRF) and the number of pulses were varied in the range of 10 – 300 kHz and 1 – 50 pulses (≈ 3 – 150 mJ), respectively, to study the effects of power deposition rate and total energy deposition on the flame development rate. It was found that lowering the PRF increased the flame development rate, as long as the ignition kernel had high probability for success. It was also found that greater numbers of pulses increased the flame development rate, but was much more effective at 10 kHz PRF as compared to 300 kHz PRF.
KW - Ignition
KW - Nanosecond pulsed discharge
KW - Plasma assisted combustion
UR - https://www.scopus.com/pages/publications/85048998756
M3 - Paper
T2 - 10th U.S. National Combustion Meeting
Y2 - 23 April 2017 through 26 April 2017
ER -