A general modeling framework was developed for predicting the mass throughput of a near-adiabatic compressor operating at 140 bar. First, a 2D computational fluid dynamics (CFD) model was developed to simulate compression, expansion, fluid flow and heat transfer inside a piston-barrel assembly where semi-empirical check-valve flow physics was implemented. Second, for rapid sizing, prototyping and exploration, a numerical macroscopic model was developed to assist and replicate CFD results with significantly less computational resources. These models were compared with experiments and the shortcomings of 2D CFD simulations were discussed.