Three-dimensional simulation of the stellar wind of HD 226868 with an X-ray luminosity equal to 3.3 × 10³⁷ erg s^-1 corresponding to the high/soft X-ray state of Cygnus X-1. α is set to 0.6. η = η(ξ), and k = k(ξ) are functions of ξ. Columns show various cross sections throughout the computational volume. All mutually perpendicular planes are centred on the compact companion and are defined as x = D, y = 0, z = 0. The displayed quantities are the density distribution (the top panels), the velocity magnitude (the middle panels), and the ionization parameter ξ (bottom panels). (This figure is available in colour in the electronic version of the paper.)