Influence of boundary conditions on downstream behaviour of eulerian lagrangian simulations of ammonia sprays

Conference item

Shipping accounts for roughly 3% of global emissions, set to rise to 10% by 2050 in a business-asusual scenario. To reduce maritime emissions, ammonia has been suggested as a carbon independent energy vector. Using ammonia for this purpose will initially require a detailed understanding of its behaviour inside combustion applications. Ammonia has a high saturation pressure, so ammonia sprays are regularly superheated. Under superheated conditions, liquids in contact with rough surfaces exhibit heterogeneous nucleation of a gaseous phase, hence contact between the liquid ammonia and injector wall can lead to vapour generation within the nozzle and a two-phase flow at the nozzle exit. Typically, Volume of Fluid simulations are used to examine behaviour in the near nozzle region, however these are computationally expensive and need to be carefully coupled with later Lagrangian Parcel Tracking (LPT) simulations to model the full spray plume. This study explores the effect of varying boundary conditions in the nozzle on downstream plume characteristics within the LPT simulation framework and compares these results with LPT results in the absence of nozzle geometry. To reproduce nucleation effects, a time-varying inflow boundary condition has been established along the nozzle wall, using a user-defined function to couple the inflow rate to the liquid flow rate. The results show that modifications to the pressure condition in the nozzle wall influence both spray penetration and radial distribution of spray mass, with an increase in spray plume width induced in flash boiling cases

Authors: Bundred, D; Leach, F

• Publication status: Accepted
• Peer review status: Peer reviewed
• Publisher: International Association for Shell and Spatial Structures (IASS)
• Acceptance date: 2025-06-09
• Event title: 33rd European Meeting on Liquid Atomization and Spray Systems (ILASS 2025)
• Event location: Lund, Sweden
• Event website: http://ilasseurope2025.se/
• Event start date: 2025-08-31
• Event end date: 2025-09-04
• Language: English