Analysis and control of transient aero-elastic response of teetering rotor on the shipboard

To investigate the problem of transient dynamic aero-elastic response of teetering rotor engagement and disengagement during shipboard operations,finite rotation of teeter angle was introduced as generalized coordinate based on the moderate deflection beam model.Nonlinear quasi-steady aerodynamic model was adopted and the flow field was determined by the test data.According to the Hamilton principle,dynamic equations were derived based on the generalized force formation.Calculation results are in good agreement with the test data and the data from other literatures.Result shows that teetering rotor blade tip has the danger of touching fuselage because of the excess flapping motion during shipboard operations.Some methods of controlling blade excess flapping are discussed.Installation of the blade flap restraint device can restrict the blade excess flapping.Increasing collective pitch has contrary effect.Cyclic pitch control has some effect on the blade flapping motion.The blade excess flapping motion can be evidently reduced by the control of the rotor speed.