The aerodynamical instability of circular profiles systems

The Ljapunov´s instability condition of equilibrium states for arbitrary profiles in an air flow, is used for investigations of instability of circular profiles systems. The hypothesis about the additivity of aerodynamical characteristics has been formulated for special systems of bad-streamlined profiles. This hypothesis was examined by experiments in a wind tunnel of Zhoukovsky Central Aerohydrodynamical Institute. The calculation method of aerodynamical characteristics is given (for example, the cooling system tubes of atomic reactors, the bundle conductors of overhead electrical lines). The aerodynamical instability´s domains about attack´s angles are determined.