Computational investigation on combustion efficiency in jet engines using Lagrangian method

Abstract Multiphase fuels, such as liquid fuels with dispersed nanoparticles or secondary phases, exhibit complex interactions involving atomization, evaporation, turbulence, and heat transfer. In particular, the size of fuel droplets significantly influences combustion characteristics, as it governs evaporation rate, mixing efficiency, and flame stability. Smaller droplets tend to evaporate rapidly and promote better fuel–air mixing, while larger droplets may lead to incomplete combustion and reduced efficiency. In this study, a comprehensive computational investigation is conducted to analyze the effect of droplet diameter on the thermohydraulic and combustion characteristics of multiphase fuel sprays within a jet engine combustor. The simulations account for droplet breakup, coalescence, and vaporization processes, as well as the inter-phase transfer of momentum, heat, and mass between the liquid and gas phases. A coupled Eulerian multiphase approach is utilized to resolve the carrier gas flow field, turbulence effects, and the spatial distribution of fuel droplets of varying diameters. Furthermore, the influence of nanoparticle-enhanced liquid fuels (NELF) on droplet thermophysical behavior such as improved thermal conductivity, modified viscosity, and altered latent heat of vaporization is examined to evaluate their potential in enhancing combustion performance.