Abstract:

With the aim of developing a new rotor system, a method is presented for calculation of stability and controllability of helicopter with hingeless rotor. The effects of nonuniformity of rotor induced velocity distribution and blade flapping elasticity are taken into account and investigated in detail.It is the first time that the first harmonic term of rotor induced velocity distribution derived from the generalized vortex theory of rotor is employed and a close form of equation for the induced velocity and circulation is established. Finally, analytic formulae suitable to engineering application are given, which consider the effects of motion parameter, control parameter, blade flapping elasticity and so on. Also, the effect of the second flapping mode on stability and controllability of helicopter with hingeless rotor is discussed in an all-round way. The calculations show that only the first flapping bending mode should be taken into account in stability and controllability calculation of helicopter with hinge-less rotor in the range of μ<0.3.Finally, a typical helicopter Bo-105 is taken as a numerical example, and it is found that the results are in good agreement with its flight-teet data.