TY - JOUR

T1 - Numerical modeling of combustion in gas engines with prechamber ignition

AU - Nguyen, Hoang Dung

AU - Kuppa, Kalyan

AU - Dohrmann, Sabine

AU - Korb, Benjamin

AU - Dinkelacker, Friedrich

N1 - Publisher Copyright: © IMechE 2024.

PY - 2024/8

Y1 - 2024/8

N2 - A numerical model is developed to predict the combustion processes in large-bore gas engines featuring prechamber ignition systems and being coupled with Computational Fluid Dynamics (CFD). The proposed combustion model is based on the simultaneous modeling of premixed and partially-premixed flames by an extended progress variable approach. By introducing an additional fuel scalar to track the externally injected fuel of the scavenged prechamber and depending on a gradient criteria of the fuel scalar, regions of locally premixed or partially-premixed state can be differentiated. The reaction rate for premixed combustion is described through a turbulent flame speed closure approach, whereas the partially-premixed combustion is described by a pre-tabulated flamelet chemistry approach. For the validation of the combustion model and its performance in the different flame propagation phases, that is, prechamber flame ignition and main-chamber flame propagation, experimental data of two large-bore gas engines with different operating conditions, prechamber configurations and engine geometries are taken into account. A good agreement of the simulations with the experimental results is shown for the variety of operating conditions and engine configurations. The developed combustion model is able to predict the combustion process in the prechamber as well as the ignition of the main chamber charge by means of the protruding flame jets through the prechamber nozzles. The prechamber ignition system accelerates the early flame phase and hence shortens the burning duration due to the deep-penetrating and turbulence-inducing flame jets in comparison to a conventional spark plug engine.

AB - A numerical model is developed to predict the combustion processes in large-bore gas engines featuring prechamber ignition systems and being coupled with Computational Fluid Dynamics (CFD). The proposed combustion model is based on the simultaneous modeling of premixed and partially-premixed flames by an extended progress variable approach. By introducing an additional fuel scalar to track the externally injected fuel of the scavenged prechamber and depending on a gradient criteria of the fuel scalar, regions of locally premixed or partially-premixed state can be differentiated. The reaction rate for premixed combustion is described through a turbulent flame speed closure approach, whereas the partially-premixed combustion is described by a pre-tabulated flamelet chemistry approach. For the validation of the combustion model and its performance in the different flame propagation phases, that is, prechamber flame ignition and main-chamber flame propagation, experimental data of two large-bore gas engines with different operating conditions, prechamber configurations and engine geometries are taken into account. A good agreement of the simulations with the experimental results is shown for the variety of operating conditions and engine configurations. The developed combustion model is able to predict the combustion process in the prechamber as well as the ignition of the main chamber charge by means of the protruding flame jets through the prechamber nozzles. The prechamber ignition system accelerates the early flame phase and hence shortens the burning duration due to the deep-penetrating and turbulence-inducing flame jets in comparison to a conventional spark plug engine.

KW - flame jet ignition

KW - Gas engine

KW - lean-burn

KW - natural gas

KW - optical engine

KW - scavenged prechamber

UR - http://www.scopus.com/inward/record.url?scp=85189990223&partnerID=8YFLogxK

U2 - 10.1177/14680874241239430

DO - 10.1177/14680874241239430

M3 - Article

AN - SCOPUS:85189990223

VL - 25

SP - 1561

EP - 1574

JO - International Journal of Engine Research

JF - International Journal of Engine Research

SN - 1468-0874

IS - 8

ER -