Thermal boundary layer near roughnesses in turbulent Rayleigh-Bénard convection: flow structure and multistability
type: Distribution
access URL: https://hal.science/hal-00920342
format: HTML
issued: 2026-05-07T18:24:11.391445
modified: 2026-05-07T18:24:11.374676

test_moissonnage_selune
type: Agent

Thermal boundary layer near roughnesses in turbulent Rayleigh-Bénard convection: flow structure and multistability
type: Dataset
contact point: Organization
  fn: CCSD
keyword: natural-convection
keyword: 4727te-4727nb
keyword: boundary-layer-turbulence
keyword: journal-articles
keyword: physmecameflphysics-physicsmechanics-physicsfluid-mechanics-physicsclass-ph
keyword: benard-convection
keyword: infoeu-reposemanticsarticle
keyword: confined-flow
keyword: spimecameflengineering-sciences-physicsmechanics-physicsmed-phfluids-mechanics-physicsc
landing page: 1070-6631
description: We present global heat-transfer and local temperature measurements, in an asymmetric parallelepiped Rayleigh-B ́enard cell, in which controlled square-studs roughnesses have been added. A global heat transfer enhancement arises when the thickness of the boundary layer matches the height of the roughnesses. The enhanced regime exhibits an increase of the heat transfer scaling. Local temperature measurements have been carried out in the range of parameters where the enhancement of the global heat transfer is observed. They show that the boundary layer at the top of the square-stub roughness is thinner than the boundary layer of a smooth plate, which accounts for most of the heat-transfer enhancement. We also report multistability at long time scales between two enhanced heat-transfer regimes. The flow structure of both regimes is imaged with background-oriented synthetic Schlieren and reveals intermittent bursts of coherent plumes.
issued: 2026-05-07T18:24:11.386793
language: en
modified: 2026-05-07T18:24:11.386797