Member of our project and Steering Committee, Michał Lewandowski, engaged in work performed within Work Package 1 and Work Package 3 working at NTNU, presented his findings regarding numerical simulations during Global CONVERGE User Conference. Presentation titled “Simulations of direct injection of liquid ammonia spray in CI engine using Lagrangian approach” concluded current development of simulations which aim at supporting the development of an ammonia injection strategy in an agriculture vehicle driven by a compression ignition (CI) engine fueled with ammonia and biodiesel as ignition promoter.
Study concerned numerical analysis of ammonia spray using a Lagrangian solver. Direct injection of liquid ammonia into compression ignition engine can possibly improve combustion of this difficult fuel, but it is also a relatively novel approach and thus not fully explored. Ammonia has a high latent heat of vaporization, and its direct liquid injection will cause a cooling effect that has to be considered and assessed. Additionally, due to its high vapor pressures at low temperatures, a flash boiling phenomenon is expected, posing some challenges for numerical modelling. The ammonia spray characteristics with GDI injector were used from Pelé et al. [Fuels (2021), 2, 253-271]. The crucial models for capturing the flash boiling spray characteristics were identified and further assessed. Attention was paid mainly to the vaporization model (accounting for external flash boiling, which intensifies vaporization), spray breakup model parameters, and spray angles. Further, the findings have been projected and adopted in the single-cylinder Hatz engine simulations at different injection timings.