Optical diagnostics on the pre-chamber jet and main chamber ignition in the active pre-chamber combustion (PCC)
| Autor: | Emre Cenker, Gaetano Magnotti, Qinglong Tang, Bengt Johansson, Junseok Chang, Ponnya Hlaing, Priybrat Sharma, Ramgopal Sampath, Manuel Alejandro Echeverri Marquez, Moez Ben Houidi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Jet (fluid)
Materials science 010304 chemical physics General Chemical Engineering Nozzle General Physics and Astronomy Energy Engineering and Power Technology 02 engineering and technology General Chemistry Penetration (firestop) Mechanics Combustion 01 natural sciences Methane Cylinder (engine) law.invention Ignition system chemistry.chemical_compound Fuel Technology 020401 chemical engineering chemistry law 0103 physical sciences 0204 chemical engineering Body orifice |
| Zdroj: | Combustion and Flame. 228:218-235 |
| ISSN: | 0010-2180 |
| DOI: | 10.1016/j.combustflame.2021.02.001 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect