A Numerical and Experimental Investigation on Different Strategies to Evaluate Heat Release Rate and Performance of a Passive Pre-Chamber Ignition System

Sabatino, Francesco Di; Novella, Ricardo; Ekoto, Isaac

doi:10.4271/2022-01-0386

Cited by 2 publications

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The maximum pressure differential ( Δ p max ) during the positive impulse is an important parameter that directly relates to jet momentum into the MC, with higher values correlated to faster jet penetration rates. 50 Values of Δ p max are plotted in Figure 7 as a function of main charge ϕ out to the achieved lean limit of ϕ ≈ 0.7 for evaluated PC geometries and ignition systems. For PCs equipped with the ISP igniter, PC 2 had the highest value of Δ p max at 10 bar, followed by PC 1 with a value of 7 bar and PC 3 at 4 bar.…”

Section: Resultsmentioning

confidence: 99%

Investigation of the effects of passive pre-chamber nozzle pattern and ignition system on engine performance and emissions

Sabatino

Novella

Ekoto

2022

International Journal of Engine Research

Self Cite

View full text Add to dashboard Cite

The impact of passive pre-chamber (PC) internal volume, nozzle hole pattern (i.e. with and without a central axial nozzle), and PC igniter plug type on performance and emissions was investigated in an optically accessible, single-cylinder, gasoline research engine. The two PC igniter plugs investigated were a conventional inductive coil spark plug and a nanosecond repetitively pulsed (NRP) plasma discharge system previously demonstrated to accelerate early flame propagation. The baseline PC design featured a funnel shaped internal volume with a PC tip that contained six radial nozzles and a larger central axial nozzle. Two additional PC tip geometries were evaluated where either the baseline internal volume was increased or the axial nozzle was removed and the radial nozzle diameters were increased. A sweep of charge equivalence ratios ( ϕ) from nearly stoichiometric to the lean limit was performed for a fixed engine speed (1300 revolutions per minute), and engine load (3.5 bar gross indicated mean effective pressure). Time-resolved PC and main chamber (MC) pressure data as well as MC emissions data were collected to analyze engine performance and emissions characteristics. Combustion in the MC was further investigated using high-speed excited methylidyne radical (CH*) chemiluminescence imaging. Collected results highlighted that while all PC tips and ignition systems exhibited similar performance and emissions down to ϕ = 0.8, relevant differences in thermal efficiency and emissions for leaner charge mixtures were observed, with the results highly dependent on the nozzle pattern and ignition system. Major deviations were correlated to preferential de-pressurization of the PC through the axial nozzle for lean conditions that was not observed for mixture conditions closer to stoichiometric. Results show that a combination of radial and axial nozzle patterns in the PC extended lean-stability limits at the low-load condition evaluated. Further benefits were observed with the use of NRP ignition systems due to faster combustion within the PC volume provided that the volume was sufficiently large.

show abstract