Rotor blade design and dynamic characteristics analysis of unmanned helicopter
The widespread application of composite materials in blades also makes the force and stiffness characteris-tics of blades more complex than traditional blades.In order to reduce the dynamic stress and vibration level of rotor blades,it is necessary to analyze the dynamic characteristics of rotor blades.The overall parameters of the rotor and the aerodynamic parameters of the blade are designed.The CFD method is used to analyze the aerodynamic charac-teristics of the rotor in hover.The three-dimensional nonlinear elastic model of the blade is decomposed into a two-dimensional linear profile model and a one-dimensional nonlinear beam model for dynamic characteristics analysis.The results show that the rotor can successfully pull up the 230 kg unmanned helicopter,the hover efficiency is greater than 0.65,the natural frequency of the blade under the working speed keeps a certain range with the frequen-cy of the aerodynamic excitation force below the 8th order,avoid the speed resonance region and meet the require-ments of the blade dynamics design.