@article{6e948d71e3e14a5e9fa819a3a1f95d99,
title = "Wave equation for sound in fluids with vorticity",
abstract = "We use Clebsch potentials and an action principle to derive a complete closed system of gauge-invariant equations for sound superposed on a general background flow. Our system reduces to the Unruh [Phys. Rev. Lett. 46 (1981) 1351] and Pierce [J. Acoust. Soc. Am. 87 (1990) 2292] wave equations when the flow is irrotational, or slowly varying. We illustrate our formalism by applying it to waves propagating in a uniformly rotating fluid where the sound modes hybridize with inertial waves.",
keywords = "General linear acoustics, Sound in flows",
author = "Bergliaffa, {Santiago Esteban Perez} and Katrina Hibberd and Michael Stone and Matt Visser",
note = "Funding Information: MS was supported by the NSF (USA) under grant DMR-98-17941. SEPB was supported by FAPERj (Brazil). MV was initially supported by the US Department of Energy, and subsequently by the Marsden Fund (administered by the Royal Society of New Zealand, RSNZ). KEH was supported by the Ministerio de Educacion y Cultura, Espa{\~n}a, and subsequently by the Funda{\c c}{\~a}o para a Ci{\^e}ncia e a Tecnologia, Portugal. This work was begun during the workshop Analog models of General Relativity at CBPF, the Brazilian Center for Research in Physics, located in Urca, Rio de Janeiro, Brazil. MV and MS thank the center for their hospitality and for hosting the workshop. ",
year = "2004",
month = apr,
day = "15",
doi = "10.1016/j.physd.2003.11.007",
language = "English (US)",
volume = "191",
pages = "121--136",
journal = "Physica D: Nonlinear Phenomena",
issn = "0167-2789",
publisher = "Elsevier B.V.",
number = "1-2",
}