Published data on flat grid purges allow to evaluate the efficiency of blade devices with different kinematic scheme of stages and design parameters. The authors present the main provisions of the calculation program algorithm and some results of numerical analysis of the efficiency of flat grids of axial stages with different combinations of design parameters. The content of the article and the computer program are addressed to people who are improving their knowledge of gas dynamics of axial compressors. Some of the results may be of interest to specialists working professionally in this field.