Phys.org December 13, 2022
Understanding the acoustic scattering and radiation force and torque of an object is important in various fields, such as underwater communication, acoustic imaging, and noninvasive characterization, as well as biomedical ultrasound. An international team of researchers (Saudi Arabia, UK, USA – University of Illinois) studied scattering off cylindrical objects in spinning motion around the axis of rotational symmetry to investigate the radiation force and torque induced by various incident signals, e.g., cylindrical diverging and converging beams as well as quasi-Gaussian beams of different orders. The study assumed that the acoustic parameters of the objects (density and compressibility) were identical to those of the surrounding medium, to isolate the effects purely attributed to rotation. They showed that a spinning inhomogeneous object also played a prominent role for generating torque with single plane waves. According to the researchers their findings may add to the current interest in time-varying and moving metamaterials and open vistas in manipulation of movement and position of ultra-small objects via acoustic beams…read more. Open Access TECHNICAL ARTICLEÂ
|| and arg(p)/Ď€ of total pressure in the presence of a spinning cylinder with radius a = 0.35 m… Credit: Applied Physics Letters, Volume 121, Issue 14, 05 October 2022Â