Technical Paper
Numerical Analysis of Mixing of Bio-Hybrid Fuels in a Direct Injection Engine with a Pre-Chamber Ignition System
2024-04-09
2024-01-2619
Pre-chamber ignition systems enable a thermal efficiency increase and can reduce NOx emissions of internal combustion engines under lean conditions. Under lean conditions, the fuel distribution in the main- and pre-chamber plays a crucial rule to achieve a stable and efficient combustion of bio-hybrid fuels. The main-chamber injection parameters, liquid spray motion, and evaporation rate mainly define the initial fuel vapor distribution. The production and convection of turbulence of the main-chamber flow field is responsible for the subsequent fuel-air mixing process and determines the fuel entrainment into the pre-chamber. To analyze the mixing of bio-hybrid fuels in pre-chamber systems, large-eddy simulations with high mesh resolution are performed to accurately resolve the relevant turbulent scales. The Navier-Stokes equations for compressible flow are solved numerically using a hierarchical Cartesian mesh based finite-volume method.