Bubble-laden thermals in supersaturated water Articles uri icon

publication date

  • January 2021

start page

  • A31-1

end page

  • A31-16

volume

  • 924

International Standard Serial Number (ISSN)

  • 0022-1120

Electronic International Standard Serial Number (EISSN)

  • 1469-7645

abstract

  • Bubble-laden thermals provide a formidable gas transport mechanism responsible, for
    instance, for the explosive foaming-up process during the beer tapping prank, or the
    infamous gas eruption of Lake Nyos in 1986. In this work we investigate experimentally
    the growth and motion of laser-induced turbulent thermals in a carbonated water solution
    with surfactants. One of the novelties of this study is that we are able to quantify with high
    temporal resolution the rate at which the gas volume contained in the bubbles grows. After
    an initial transient stage, the gas bubble and entrained liquid volumes of the thermal both
    grow as a cubic power of time. The buoyancy generation rate is well explained by the mass
    transfer scaling expected for individual bubbles. In contrast, the thermal rise velocity does
    not adhere to any particular scaling law. These facts lie in qualitative agreement with a
    phenomenological model, based on classical models for turbulent thermals, that takes into
    account buoyancy generation.

subjects

  • Mechanical Engineering

keywords

  • plumes/thermals; bubble dynamics; coupled diffusion and flow