The work was supported by the Technology Agency of the Czech Republic under the grant TH02020057. Institutional support RVO 61388998 is also gratefully acknowledged.Numerical simulations of the supersonic flow have shown the significant effect of the
prescription of the outlet boundary condition. Simulations carried out for the standard
computational domain with the output behind the blade cascade and/or for the computational domain corresponding to the experimental arrangement have shown that numerical results obtained on the basis of the numerical optimization correspond quite well to experimental data (see Louda et al.). The agreement of predicted flow fields and main parameters including energy losses is acceptable
