Numerical analysis of a miniature multi-stage compressor at variable altitudes based on stages-in-series method

•Stages-in-series numerical model for a multi-stage swash-plate compressor is built.•Real-time variations of gas properties in the inter-stage channels are considered.•The last stage cylinder of the compressor has the worst working conditions at high altitudes.•The indicated power required by the compressor drops by about 20 % for every 2000 m increase in altitude.