Pc Bunniss

A Combined Numerical/Experimental Continuation Approach Applied to Nonlinear Rotor Dynamics

Presented with complex systems exhibiting nonlinear behaviour, engineers in industry may face difficulties in understanding the system, both from a mathematical modeling perspective and also when trying to set up representative experiments. Here, a systematic approach combining numerical and experimental parameter continuation is applied to the investigation of complex nonlinear rotor behaviour. The aim is to show the benefits of co-ordinating numerical and physical tests in order to build a mathematical model that adequately captures the system dynamics. In this study the problem involves a dynamical system operating in a nonlinear periodic manner, with constraints on its states and parameters. The system is an autogyro rotor for which the approach generates a simple mathematical model yielding multiple possible autorotative conditions not previously identified in a systematic way; it also provides an explanation for unsafe operating scenarios.

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.Copyright

Proceedings of the ASME Design Engineering Technical Conference

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.Copyright

7th International Conference on Multibody Systems, Nonlinear Dynamics and Control (IDETC), San Diego, CA, USA

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.Copyright