On one type of models of spherical stellar clusters.

The estimates of the time of star transitions between halo and core in spherical clusters as a result of stellar encounters are given. Numerical integration of gross-evolution equations for quasi-stationary and nonstationary (in a regular field) stellar clusters has been performed. There are three possible types of "halo-core" structure evolution in the quasi-stationary stellar clusters depending upon the initial conditions. All the open stellar clusters evolve near a certain sequence in the space of gross-parameters ξ and μ during the most of their lifetime. The parameters ξ and μ are the ratio of core radius to halo radius and the ratio of core mass to halo mass, respectively. The majority of open clusters must be concentrated near the sequence ξ = ξ(μ). This sequence corresponds to the balance of rates of transitions between core and halo during the cluster relaxation. The results of comparison of the author's cluster model calculations with observations and numerical N-body experiments are discussed.