Interaction between internal and external friction in rotation of vane with viscous filling

•A mathematical model is created for a vane with filling in the constant flow.•Dynamical system was computed for ranges of parameters.•The vane has different modes of motion depending on initial conditions.•Results of calculations presented in plane friction coefficient – medium density.•The region of attraction of the axial rotation of the system is relatively large. Rotation of the four-blade axisymmetric vane around the fixed point is considered in the constant flow of medium. The vane contains the cavity that is filled by viscous filling. Aerodynamic force acts upon the blades of the vane. The quasi-steady approach is used for modeling an aerodynamic load. A case for blades with low fineness is considered. Nonlinear approximation of the aerodynamic fineness function is used. Internal friction is modeled as the linear function between the angular speed of the vane and the vortex vector of the filling. This is a mechanical system with variable dissipation. Corresponding dynamic system is simulated for different values of the density of external medium and the coefficient of the internal friction. Two types of the vane configuration (oblate and oblong) are considered. Interaction between the external aerodynamic load and the internal friction is observed. Areas are found, where the steady axial rotation is not globally attracting.