Аннотация:Dynamics of an aerodynamic double pendulum is considered under the assumption that the spring in the first joint is nonlinear elastic. This object is an aeroelastic system with two degrees of freedom, which can be considered as a source of energy. Numerical simulation of the behavior of the pendulum is performed. It is shown that it is possible to choose parameters in such a way as to ensure the instability of the equilibrium and the existence of limit cycle oscillations. The influence of characteristics of the joint spring upon the amplitude and frequency of the cycles is analyzed. In particular, it is shown that the amplitude non-monotonically depends on the parameter characterizing the cubic nonlinearity of the stiffness. In the same time, frequency monotonically increases as this parameter increases. The presence of limit cycle oscillations means that the system in question is capable of harvesting energy from the flow. However, thorough parametric analysis is still required in order to determine the optimal design and parameters of such systems.