Immiscible Rayleigh-Taylor turbulence: Implications for bacterial degradation in oil spills

• 成果类型: Article
• 署名作者: Brizzolara, Stefano; Naudascher, Robert; Rosti, Marco Edoardo; Stocker, Roman; Boffetta, Guido; Mazzino, Andrea; Holzner, Markus
• 署名单位: Swiss Federal Institutes of Technology Domain; ETH Zurich; Swiss Federal Institutes of Technology Domain; Swiss Federal Institute for Forest, Snow & Landscape Research; Okinawa Institute of Science & Technology Graduate University; University of Turin; Gran Sasso Science Institute (GSSI); Istituto Nazionale di Fisica Nucleare (INFN); University of Turin; University of Genoa; Istituto Nazionale di Fisica Nucleare (INFN); University of Genoa; Gran Sasso Science Institute (GSSI); BOKU University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9137
• DOI: 10.1073/pnas.2311798121
• 发表日期: 2024-03-12
• 关键词: numerical simulations; subsea blowout; instability; shear; interface; biodegradation; waves; FLOWS; MODEL

摘要

An unstable density stratification between two fluids mixes spontaneously under the effect of gravity, a phenomenon known as Rayleigh-Taylor (RT) turbulence. If the two fluids are immiscible, for example, oil and water, surface tension prevents intermixing at the molecular level. However, turbulence fragments one fluid into the other, generating an emulsion in which the typical droplet size decreases over time as a result of the competition between the rising kinetic energy and the surface energy density. Even though the first phenomenological theory describing this emulsification process was derived many years ago, it has remained elusive to experimental verification, hampering our ability to predict the fate of oil in applications such as deep -water spills. Here, we provide the first experimental and numerical verification of the immiscible RT turbulence theory, unveiling a unique turbulent state that originates at the oil-water interface due to the interaction of multiple capillary waves. We show that a single, non -dimensional, and time -independent parameter controls the range of validity of the theory. Our findings have wide-ranging implications for the understanding of the mixing of immiscible fluids. This includes in particular oil spills, where our work enables the prediction of the oil-water interface dynamics that ultimately determine the rate of oil biodegradation by marine bacteria.