Evolution of the density distribution in the equatorial plane computed with the radiation hydrodynamic model during the convergence process towards a new stationary solution. The uppermost left panel represents the state close to the conditions set up by the radial model. The bottom right panel captures the nearly steady-state solution corresponding to the newly included forces – the Coriolis force and the tangential forces caused by the pressure gradients. The white index in the upper right corner of each panel indicates an evolutionary time expressed in the units of the orbital periods. The red cross and asterisk show the position of the black hole and the centre of the supergiant, resp.