Logarithmic Mean Temperature Profiles and Their Connection to Plume Emissions in Turbulent Rayleigh-Bénard Convection

Erwin van der Poel, Rodolfo Ostilla Monico, Roberto Verzicco, Siegfried Grossmann, Detlef Lohse

Research output: Contribution to journalArticleAcademicpeer-review

24 Citations (Scopus)
89 Downloads (Pure)

Abstract

Two-dimensional simulations of Rayleigh-Bénard convection at Ra ¼ 5 × 1010 show that vertical logarithmic mean temperature profiles can be observed in regions of the boundary layer where thermal plumes are emitted. The profile is logarithmic only in these regions and not in the rest of the boundary layer where it is sheared by the large-scale wind and impacted by plumes. In addition, the logarithmic behavior is not visible in the horizontal average. The findings reveal that the temperature profiles are strongly connected to thermal plume emission, and they support a perception that parts of the boundary layer can be turbulent while others are not. The transition to the ultimate regime, in which the boundary layers are considered to be fully turbulent, can therefore be understood as a gradual increase in the fraction of the plume-emitting (“turbulent”) regions of the boundary layer.
Original languageEnglish
Article number154501
Number of pages5
JournalPhysical review letters
Volume115
Issue number154501
DOIs
Publication statusPublished - 5 Oct 2015

Keywords

  • IR-97496
  • METIS-312048

Fingerprint Dive into the research topics of 'Logarithmic Mean Temperature Profiles and Their Connection to Plume Emissions in Turbulent Rayleigh-Bénard Convection'. Together they form a unique fingerprint.

  • Cite this