Experimental evaluation of numerical continuation and bifurcation methods applied to autogyro rotor blade aeromechanical stability

This paper presents a systematic assessment of the use of continuation and bifurcation techniques, in investigating the nonlinear periodic behaviour of rotor blades in forward autorotation. Our aim is to illustrate the potential of these tools in revealing complex blade dynamics, when used in combination (not necessarily in real time) with physical testing. We show a simple procedure to promote understanding of an existing engineering instability problem when uncertainties in the numerical modelling are present. It is proposed that continuation and bifurcation methods can play a significant role in developing numerical/experimental techniques for studying blade dynamics for both autorotating and powered rotors, which can be applied even at the preliminary design phase.