Computational assessment of effects of throat diameter on combustion and turbulence characteristics in a pre-chamber engine

A Computational Assessment of Combustion Submodels for Predictive Simulations of Pre-Chamber Combustion Engines

“…The 3D contours reveal that, although the PCs have 12 nozzles, it mostly relies on the major activity of 6 bottom nozzles. Silva et al [21] discussed this unusual behavior, which is a combination of high-speed flow along the throat, followed by transonic flow at the top nozzle location, which prevents the comparable behavior to the bottom nozzles. Moreover, a major distinction in the jet topologies is observed; while G-Equation shows small jet exiting the top nozzles, the MZ-WSR only manifests the six bottom nozzle jets.…”

“…𝑢 ′ , was obtained from the transport equation for the turbulent kinetic energy (k) under the assumption of homogeneous and isotropic turbulence. Additional discussion can be found in previous works [21].…”

“…The G-equation model was utilized in numerous works. Silva et al [21] utilized it and successfully reproduced the pressure evolutions behavior of a narrow throat PC engine operated with methane. Kim et al [22] proposed that the turbulence-chemistry constants in Peters's relation could be tuned to achieve correct pressure prediction, while the current work preserves the originally proposed turbulent constant values.…”

“…Furthermore, the additional feature of a narrow throat and double layer of nozzles prechamber utilized in the current work promotes distinguishable nozzle behavior, thus is suitable for additional assessment. In addition, it is documented that both pre-and main chambers combustion occur with a large variation of turbulencechemistry interaction (TCI) -time scales and length scales [21,28] therefore, an adequate combustion model for predictive prechamber combustion modeling must account for these ample scales. A recent work by Tang et al [27] performed in an optical engine suggested that, under stable engine operating conditions, a flame-based phenomenon is likely to represent the PC combustion.…”

“…Detailed explanations of experimental and numerical setups are discussed in previous works [21] and will be briefly quoted in the current work. The experiments were conducted at KAUST; the schematic of the testbed is found in [7,8,10].…”