An approximate calculation of the working cycle for a specific cylinder of your choice can be carried out with the program given here. The original version of this program was compiled by Mr. Matthias Kornfeld, TU Vienna on the occasion of the 5th EFRC- workshop in 2008.
When using this program, you can choose quality criteria for clearance volume, the compressor valves and the wear condition of the cylinder as “very good” or “less good”. According to your choice the program then defines the clearance volume ratio, the temperature and mass factor of the performance ratio, the polytropic exponent and the effective valve area in relation to the piston area. Thereby it is possible to assess the influence of these quality criteria on compressor throughput and power consumption.
The overall proceedings in the working chamber are called the working cycle. For the first consideration, we assume the compressor working without any losses. The clearance volume as is necessary by the design is V0. By cooling the cylinder, the compression will become polytropic, which is between the isothermal and isentropic compression. The working cycle can be shown in a p,V-diagram (indicator diagram), which shows both the change in the conditions of state and the changes of masses, see Figure 5.1.