Investigation of two-stage compression of gas

A numerical investigation is performed of two-stage compression of gas with different modes of transfer of gas between the chambers of a free-piston ballistic facility. The calculation results demonstrate that the temperature of two-stage compression with isobaric transfer flow is approximately 20 % higher than the temperature of compression with isochoric transfer flow and up to 40 % higher than the temperature of two-stage compression with a permanently open opening in the range of maximal values of compression pressure up to 60 atm. An experimental investigation is performed of the process in a ballistic facility with the working volume divided into two chambers. A simple method is demonstrated of realizing two-stage compression with isobaric transfer flow using a cone end piece located at the front end of the piston. The experimental results confirm theoretical analysis.