  We present numerical models for supernova remnant evolution, using a new
version of the hydrodynamical code SUPREMNA. We added cosmic ray diffusion
equation to the code scheme, employing two-fluid approximation. We investigate
the dynamics of the simulated supernova remnants with different values of
cosmic ray acceleration efficiency and diffusion coefficient. We compare the
numerical models with observational data of Tycho's and SN1006 supernova
remnants. We find models which reproduce the observed locations of the blast
wave, contact discontinuity, and reverse shock for the both remnants, thus
allowing us to estimate the contribution of cosmic ray particles into total
pressure and cosmic-ray energy losses in these supernova remnants. We derive
that the energy losses due to cosmic rays escape in Tycho's supernova remnant
are 10-20% of the kinetic energy flux and 20-50% in SN1006.
