GDI Ammonia Spray Numerical Simulation by Means of OpenFOAM

The goal of mitigating climate change has driven research to the use of carbon-free energy sources. In this regards, green hydrogen appears as one of the best options, however, its storage remains difficult and expensive. Indeed, there is room to consider the use of ammonia (an efficient hydrogen carrier) directly as a fuel for internal combustion engines or gas turbines. Currently, there are very few works in the literature describing liquid ammonia sprays, both from experimental and modeling point of view, and especially dealing with flash-boiling conditions. In this research work, the direct injection ammonia spray is modeled with the Lagrangian particle approach, building up a numerical model within the OpenFOAM framework, for transient analyses using the U-RANS approach. An evaluation of main spray modeling parameters is carried out to build a predictive Lagrangian model for ammonia based on the comparison with experiments in terms of liquid and vapor tip penetration, local values of Sauter mean diameter and global spray morphology. In this work, results of CFD simulations of ammonia spray and the comparison with experimental data are presented for different conditions, aiming to present a comparison between flash boiling and non-flashing regimes.