Project Description: In hydrodynamics, streaming in a viscous fluid is a transport phenomenon whereby steady flow is generated in the bulk of a liquid due to the attenuation of an acoustic wave. As the acoustic wave loses energy due to viscous dissipation, it simultaneously transfers momentum to the fluid. This transfer of momentum is not uniform throughout the fluid, especially near boundaries or where the acoustic field is nonuniform. This nonuniform momentum transfer, averaged over time, leads to a net, time-independent (DC) force on the fluid. This force drives a steady streaming motion in the fluid. Therefore, it is a nonlinear effect, meaning it arises from the second-order interactions of the acoustic field with the fluid. Rayleigh provided the first rigorous theoretical framework for this phenomenon, which was motivated by observations of fluid currents near vibrating objects. It eventually led to the concepts of boundary layer theory developed in works of Prandtl and later Schlichting to analyze the steady flow generated by oscillating bodies or acoustic waves, particularly focusing on the streaming within the viscous boundary layers near walls (see Landau-Lifshitz Vol. 6 paragraph 80 for further discussion).
This practicum focuses on exploring ideas related to streaming and propulsion in electronic liquids, which can manifest in nonlinear transport phenomena. These include, in particular, photogalvanic effects, second-harmonic generation, and photothermal responses.
Prerequisites: Familiarity with the basics of fluid dynamics, particularly relevant sections from Volume 6 of Landau-Lifshitz, and familiarity with the electrodynamics of continuous media from Volume 8.
Literature:
[1] Landau, L. D., & Lifshitz, E. M. (1987). Fluid Mechanics (2nd ed., Vol. 6). Pergamon Press.
[2] Landau, L. D., & Lifshitz, E. M. (1980). Electrodynamics of Continuous Media (2nd ed., Vol. 8). Pergamon Press.
[3] Sturman, B. I., & Fridkin, V. M. (1992). The Photovoltaic and Photorefractive Effects in Noncentrosymmetric Materials. Gordon and Breach Science Publishers