An experimental study of the formation of the structure of a closed vortex motion of a liquid in a vertical cylindrical container with a rotating end (disk) under various boundary conditions has been carried out. The regimes of formation of the circulating motion of a liquid with a small aspect ratio are experimentally investigated. The studies have been carried out using the Particle Image Velocimetry method in a horizontal cross-section near the interface in a cylinder and near the bottom in a gas-vortex reactor. It has been found that with a small aspect ratio in an open cylinder near the air-liquid interface, a region is formed near the axis, in which the radial velocity component is close to zero. Consequently, the circulation is not formed in the entire volume, and the efficiency of mass transfer decreases. At the same time, at a solid boundary, as well as at the liquid-liquid interface, a circulation flow of the working fluid is formed even at a small aspect ratio.