Venerdì 13 Maggio si svolgerà presso l’aula De Donato (edificio 3), un seminario dal titolo “Twist and Shout: Elastic Orbital Angular Momentum” tenuto dal Dr. Gregory James Chaplain, ricercatore del Dipartimento di Fisica e Astronomia presso l’Univeristà di Exter (UK).

Abstract:

We identify that guided flexural waves in pipes carry a well-defined orbital angular momentum (OAM), associated with the compressional dilatational potential. The transfer of elastic OAM can be achieved through the coupling of the dilatational component of ultrasonic waves in the pipe with the pressure field in a fluid in which the pipe is partially submerged; the circumferential distribution of the stress in the pipe act as a continuous phased pressure source in the fluid, resulting in the generation of Bessel-like acoustic beams. We demonstrate the existence of elastic OAM through theory and observe its transfer via simulation that is corroborated experimentally.

Speaker’s Biosketch:

Gregory is from Dundee, Scotland, where he lived until moving to Glasgow in 2012 to undertake an MSci in physics at the University of Glasgow. Afterwards he moved to Imperial College London where he obtained a PhD in applied mathematics under Prof. Richard Craster, winning the Yael Dowker Prize for best mathematics PhD thesis for his research into wave propagation effects in structured materials. He continuted at Imperial as a doctoral prize research fellow before being awarded a Research Fellowship from the Royal Commission for the Exhibiton of 1851 at the University of Exeter in 2021.
His research interests include manipulating wave propagation using structured materials and metamaterials, across a variety of wave regimes from electromagnetism to elasticity, with a focus on applications in energy harvesting and vibration control.