Palestra no auditório do CT nesta quarta-feira, dia 27/02/2013

Nesta quarta-feira, 27/02/2013, haverá uma palestra sobre Dinâmica, Controle e Colheita de Energia (Energy Harvesting), a ser proferida pelo Prof. Marian Wiercigroch da Universidade de Aberdeen (Escócia – UK) :

Título: Complex Dynamics of Pendulums for Energy Harvesting
Local: Auditório do CT (CENTRO DE TECNOLOGIA)
Horário: Quarta-feira – 27/02/2013, às 14:00

O Prof. Marian Wiercigroch aproveitará a oportunidade para falar um pouco também sobre a Universidade de Aberdeen.

O resumo da palestra e uma pequena biografia seguem abaixo.

 

Complex Dynamics of Pendulums for Energy Harvesting

Professor Marian Wiercigroch FRSE
Centre for Applied Dynamics Research,
School of Engineering, University of Aberdeen, Aberdeen, UK
m.wiercigroch@abdn.ac.uk

Abstract: Complex dynamics of pendula systems is being analysed with a view of vibrational energy harvesting and vibration isolation. The main focus of the lecture is a new concept of energy conversion [1], where a predominantly vertical oscillatory motion is being converted into rotations by means of a pendulum or pendulums system. The simplest physical configuration of this idea is a parametric pendulum operating in the fully rotational motion. Practically this can be envisaged as a floating structure excited to which pendulums are mounted at their pivots. These vertical oscillations of the structure will generate the pendulums rotational motion. Numerical, analytical and experimental studies have been undertaken on a parametric pendulum [2-4] and a pendulum excited by a planar motion [5]. They suggest the rotational motion is persisting and occurs for a large range of frequencies and excitation amplitudes, which are the main control parameters. These investigations reinforce the viability of this new concept of the energy conversion. In the lecture I outline this new concept and review the current theoretical and experimental developments. Specifically, I will present the physical and mathematical modelling of a single pendulum and a system comprised of two pendulums excited by a planar motion. Details of the experimental rig for this new two pendulums system and a correlation between the theory and experiments will be given. Detailed numerical and analytical results showing strongly nonlinear behavior will be discussed. I will conclude with a brief study on nonlinear control to maintain rotational motion.

Keywords: Nonlinear and complex system, parametric pendulum, dynamical response, oscillations, stability, energy extraction

Reeferences
[1] Wiercigroch, M., Energy conversion and extraction from oscillatory motion using pendula systems operating in rotational motion (patent pending)
[2] Xu, X. and Wiercigroch, M.., Approximate analytical Solutions for oscillatory and rotational motion of a parametric pendulum, Non. Dyn. 47, 311-320, 2007
[3] Xu, X. Pavlovskaia, E.E., Wiercigroch, M., Romeo, F. and Lenci, S., Dynamic interactions between parametric pendulum and electrodynamical shaker: Effect of non-ideal excitation source, Z. Angew. Math. Mech. 87, 172-187, 2007
[4] Horton, B., Wiercigroch, M. and Xu, X., Transient tumbling chaos and damping identification for parametric pendulum, Phil. Trans. Roy. Soc. A 366, 767-784, 2008
[5] Horton, B., Sieber, J., Thompson, J.M.T. and M Wiercigroch, M. 2011 Dynamics of the nearly parametric pendulum. Int. J. Non-linear Mech. 46, 436-442, 2011

-*- Marian Wiercigroch’s Brief Bio -*-

Professor Marian Wiercigroch educated in Poland, US and UK holds a prestigious Sixth Century Chair at the University of Aberdeen. He is a founding director the Centre for Applied Dynamics Research and a Director of Internationalisation for the College of Physical Sciences at the University of Aberdeen.

His area of research is nonlinear dynamics which he applies to various engineering problems including downhole drilling, rotor systems, underwater acoustics, fatigue and renewable energy. He is a frequent keynote speaker at major international conferences. Professor Wiercigroch has published over 250 journal and conference papers and sits on eight editorial boards of leading academic journals. He is the Editor-In-Chief of the International Journal of Mechanical Sciences.

Professor Wiercigroch is a fellow of the Institution of Mechanical Engineering and the Institute of Mathematics and Its Applications. He has received many awards and distinctions including a Senior Fulbright Scholarship and a Fellowship of the Royal Society of Edinburgh