TY - JOUR
T1 - Optical diagnostics on the pre-chamber jet and main chamber ignition in the active pre-chamber combustion (PCC)
AU - Tang, Qinglong
AU - Sampath, Ramgopal
AU - Marquez, Manuel Echeverri
AU - Sharma, Priybrat
AU - Hlaing, Ponnya
AU - Ben Houidi, Moez
AU - Cenker, Emre
AU - Chang, Junseok
AU - Magnotti, Gaetano
AU - Johansson, Bengt
N1 - KAUST Repository Item: Exported on 2021-02-19
Acknowledgements: The 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.
PY - 2021/2/15
Y1 - 2021/2/15
N2 - We 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.
AB - We 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.
UR - http://hdl.handle.net/10754/667483
UR - https://linkinghub.elsevier.com/retrieve/pii/S0010218021000638
U2 - 10.1016/j.combustflame.2021.02.001
DO - 10.1016/j.combustflame.2021.02.001
M3 - Article
SN - 0010-2180
VL - 228
SP - 218
EP - 235
JO - Combustion and Flame
JF - Combustion and Flame
ER -