Optical diagnostics on the pre-chamber jet and main chamber ignition in the active pre-chamber combustion (PCC)
Marquez, Manuel Echeverri
Ben Houidi, Moez
KAUST DepartmentClean Combustion Research Center
King Abdullah University of Science and Technology, Clean Combustion Research Center, Thuwal 23900, Saudi Arabia.
Physical Science and Engineering (PSE) Division
Mechanical Engineering Program
Embargo End Date2023-02-15
Permanent link to this recordhttp://hdl.handle.net/10754/667483
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AbstractWe studied the relationship between pre-chamber jet and main chamber ignition in the pre-chamber combustion (PCC) of an optical engine, fueled with methane and equipped with an active pre-chamber with two rows of orifices. Acetone planar laser-induced fluorescence (PLIF) and OH* chemiluminescence imaging techniques were simultaneously applied to visualize the pre-chamber jet and the reaction zone in the main chamber, respectively. The pre-chamber fueling was constant and the main chamber fueling was increased to form an ultra-lean case and a lean case with global excess air ratios (λ) of 2.3 and 1.8, respectively. Results indicate that a higher pressure difference between pre-chamber and main chamber (P) produces larger pre-chamber jet penetration speed; the maximum pre-chamber jet penetration speed appears at timing around the peak P. Over enrichment of the pre-chamber charge reduces the peak P and thus does not favor a faster pre-chamber jet discharge. In addition to the main pre-chamber jet, a weaker post jet discharge process is visualized; the former is due to the pre-chamber combustion while the latter due to the P fluctuation and the cylinder volume expansion. The post pre-chamber jet is accompanied by a post reaction zone in the ultra-lean case (λ=2.3) and there are two unburned regions in the main chamber: one is around the pre-chamber nozzle and the other between the adjacent reaction zones. These two unburned regions are consumed by flame propagation in the lean case (λ=1.8). The weak pre-chamber jet from the upper-row orifice does not produce any distinct reaction zone, indicating that the pre-chamber orifice location and arrangement on the nozzle also matters in the pre-chamber design. The pre-chamber jet penetration length is longer than that of the reaction zone during pre-chamber discharge; the penetration length difference between the pre-chamber jet and reaction zone decreases with increasing main chamber fueling.
CitationTang, Q., Sampath, R., Marquez, M. E., Sharma, P., Hlaing, P., Houidi, M. B., … Johansson, B. (2021). Optical diagnostics on the pre-chamber jet and main chamber ignition in the active pre-chamber combustion (PCC). Combustion and Flame, 228, 218–235. doi:10.1016/j.combustflame.2021.02.001
SponsorsThe paper is based upon work supported by Saudi Aramco Research and Development Center FUELCOM3 program under Master Research Agreement Number 6600024505/01. FUELCOM (Fuel Combustion for Advanced Engines) is a collaborative research undertaking between Saudi Aramco and King Abdullah University of Science and Technology (KAUST) intended to address the fundamental aspects of hydrocarbon fuel combustion in engines and develop fuel/engine design tools suitable for advanced combustion modes.
JournalCombustion and Flame