This investigation aims at quantifying the spray dynamics of diesel-like injection at the steady stage. A 1D model based on momentum flux conservation and combined with Gaussian radial profiles is derived to predict the axial and radial velocity, fuel concentration, liquid volume fraction and density distribution within the steady spray field. To validate the model over a range of conditions, global quantities such as spray tip penetration, spray cone angle, spray tip velocity, and spray volume was measured by diffused back-illumination imaging. The spray characteristics of hydrotreated vegetable oil (HVO) and European standard diesel fuel (EN590) under different ambient air conditions (36 kg/m3 and 115 kg/m3) are compared to further predict the local velocity, fuel concentration, liquid volume fraction and density distribution. The present results indicate that an accurate model of diesel-like spray evolution can be obtained for different fuel types and ambient air densities.