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Department of Physics and Astronomy
University of Mississippi

Events

Event Information:

  • Tue
    25
    Jan
    2022

    Colloquium: Physics Graduate Student Presentations

    4:00 pmLewis Hall 101

    Xinyue Gong
    Department of Physics and Astronomy
    University of Mississippi

    Hall Effect for Acoustic Waves Carrying Angular Momentum

    Acoustic waves with a twisted wave front also carry angular momentum in addition to linear momentum,in analogy to optical and quantum fields. The law of refraction states that the direction of refracted light rays is normally in the plane of incidence as they propagate across a sharp interface. Nevertheless, the refraction law is not enough to describe the angular momentum carried by refracted beams. Refracted light beams carrying angular momentum have been observed to undergo a shift in the direction that is transverse to the plane of incidence, a phenomenon that was termed as optical Hall effect. Here we pursue the first experimental observation of Hall effects for acoustic waves that carry angular momentum. Our experiment exploits the more recently developed acoustic metasurface to manipulate the wave refraction. A theoretical calculation of the wave fields is also conducted to compare with the experimental measurements. The talk will present physics related to the phenomenon, our experimental setup, and preliminary results.

     

    Guoqin Liu
    Department of Physics and Astronomy
    University of Mississippi

    Modeling and Simulations of Capillary-Gravity Wave Transmission Through a Surface Piercing Barrier

    Capillary-gravity waves are waves traveling on a fluid interface that are influenced by both the effects of surface tension and gravity. Interactions of capillary-gravity waves with boundaries in contact with a solid and air play an essential role in both fluid physics and fluid control techniques. Motion of the contact line at the three phase boundary (solid, liquid, and air) can influence the wave dynamics such as the wave frequency, damping, refraction, and transmission. Here we develop fluid dynamics modeling and numerical simulations to investigate the transmission of capillary-gravity waves through a surface piercing barrier under the effect of a pinned contact line. Our modeling is validated via a comparison with prior theory in ideal cases. We numerically reveal how the surface tension and contact lines affect the transmission in the realistic case for waves of different frequencies and barriers of different depths.

     

     

    Join Zoom Meeting

    https://olemiss.zoom.us/j/91928227187

    Meeting ID: 919 282 27187