Study Of Dynamic Stability Of Electrical Controlled Rotor

The Electrically Controlled Rotor (ECR) is a new concept rotor system which was brought out atthe beginning of this century. The ECR system uses electric actuators to drive the servo-flap locatedat the blade trailing-edge to fulfill blade pitching rather than the swashplate. The ECR system is adirection of the future development of the helicopter rotor system. But the introduction of trailingedge flaps and structure parameters changing make the dynamic stability of ECR system morecomplex. In this dissertation, research works on the modeling and analysis of the dynamic response ofthe ECR system were carried out. The main contents are as follows:1. The quasi-steady aerodynamic model of the Theodorsen model and Black&White linearinflow model were used to calculate the Aerodynamic models of the ECR system.2. The dynamic equations of blade were derived with the generalized Hamilton’s principle. Thedynamic stability of the blade motion of the coupling of flap/pitch and the coupling of lag/pitchwere analyzed by the way of transient response. Meanwhile, the model was verified by theexperimental data. The dynamic stability of the blade motion of the coupling of flap/lag wasanalyzed by eigenvalue method. Meanwhile, the model was verified by the Computational example.3. Taking Improved electronic control rotor for instance, the influence of parameters whichinclude rotor speed, root torsional stiffness, effective center of gravity position and the forward speedfor dynamic stability of the blade were studied. The results showed that the dynamic instability of theblade is more likely to happen when the electronic control rotor are in the low rotate speed, the greatroot torsional stiffness,the front place of effective center of gravity or the fast forward flight speed.Taking improved customized control rotor for instance, the influence of parameters was studied. Theresults showed that the dynamic instability of the blade is more likely to happen when the electroniccontrol rotor are in the specific rotate speed(the basic natural frequency of the flap modal is close tothe basic natural frequency of the lag modal)or the high blade preinstall angle. Taking improvedelectronic control rotor for instance, the influence of parameters for dynamic stability of the blade wasstudied. The results showed that the dynamic instability of the blade is more likely to happen whenthe electronic control rotor are in the low rotate speed, the great root torsional stiffness,the bigpreliminary angle or the fast forward flight speed.