title: Acoustic rotational manipulation using orbital angular momentum transfer.
abstract: We report on the first quantitative test of acoustic orbital angular momentum transfer to a sound absorbing object immersed in a viscous liquid. This is done by realizing an original experiment that is to spin a millimeter-size target disk using an ultrasonic vortex beam. We demonstrate the balance between the acoustic radiation torque calculated from the Brillouin stress tensor and the viscous torque evaluated from the steady state spinning frequency. Moreover, we unveil a rotational acoustic streaming phenomenon that results from the acoustic angular momentum transfer to the host fluid. We show that it lowers the viscous torque, thereby restoring the torque balance.
authors.affiliation: Université de Bordeaux, LOMA, UMR 5798, F-33400 Talence, France.
authors.forename: Andreas
authors.initials: A
authors.lastname: Anhäuser
authors.forename: Régis
authors.initials: R
authors.lastname: Wunenburger
authors.forename: Etienne
authors.initials: E
authors.lastname: Brasselet