Régimes convectifs instationnaires dans l'air en cavité à grands facteurs d'aspect : résultats expérimentaux

Martinet, B.; Haldenwang, Pierre; Labrosse, G.; Payan, J; Payan, R.

doi:10.1051/jphyslet:01982004306016100

Cited by 9 publications

(4 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both lines of equal horizontal and vertical density difference can be visualized as interference fringes. This technique was also used in other, similar experiments by Martinet et al [123,124] and by Zierep and Oertel [125]. All of these interferometric studies suffer from the disadvantage that, since the refractive index of air is not much different from 1, it was necessary to view the convection from the side, and so to integrate over the length of the convective rolls to obtain an optical path length through the convection cell sufficient to show interference fringes.…”

Section: Review Of Previous Experiments On Gas Convectionmentioning

confidence: 99%

Apparatus for the study of Rayleigh–Bénard convection in gases under pressure

Bruyn

Bodenschatz

Morris

et al. 1996

Review of Scientific Instruments

145

168

View full text Add to dashboard Cite

We review the history of experimental work on Rayleigh-Bénard convection in gases, and then describe a modern apparatus which has been used in our experiments on gas convection. This system allows the study of patterns in a cell with an aspect ratio (cell radius/fluid layer depth) as large as 100, with the cell thickness uniform to a fraction of a µm, and with the pressure controlled at the level of one part in 10 5. This level of control can yield a stability of the critical temperature difference for the convective onset of better than one part in 10 4. The convection patterns are visualized and the temperature field can be inferred using the shadowgraph technique. We describe the flow visualization and image processing necessary for this. Some interesting results obtained with the system are briefly summarized.

show abstract

Section: Review Of Previous Experiments On Gas Convectionmentioning

confidence: 99%

Apparatus for the study of Rayleigh–Bénard convection in gases under pressure

Bruyn

Bodenschatz

Morris

et al. 1996

Review of Scientific Instruments

145

168

View full text Add to dashboard Cite

show abstract

“…The occurrence of turbulence is not so well defined either; one possible behaviour in experiments is a continuous grow-up of noise versus R and an exponential decay of its spectrum versus frequency [4]. Nevertheless some experiments [5] do not at all follow these rules.…”

mentioning

confidence: 99%

“…This boundary condition is less important but it is difficult to say if this is related to the conductivity of the sidewalls or rather to their small aspectratio (f = 6). 5. Amplitude function in the axisymmetric pattern.…”

mentioning

confidence: 99%

Rayleigh-Bénard convective structures in a cylindrical container

Croquette¹,

Mory²,

Schosseler³

1983

J. Phys. France

View full text Add to dashboard Cite

2014 Dans cet article nous faisons une étude des différentes structures convectives que l'on peut observer dans une géométrie cylindrique telle que le diamètre soit égal à 20 fois la hauteur. Pour un nombre de Prandtl de 380, ces structures apparaissent désordonnées mais stationnaires (après une phase de relaxation). Nous montrons que ces structures désordonnées sont plus stables que les solutions axisymétriques et nous indiquons comment les conditions aux limites jouent un rôle essentiel sur la stabilité de ces dernières. Enfin, nous considérons deux types de défauts, que l'on rencontre fréquemment dans les structures désordonnées. Nous les étudions par l'intermédiaire de leur champ de vitesse obtenu par vélocimétrie laser. Nous montrons que cette méthode nous permet une comparaison quantitative avec des théories récentes.

show abstract

“…The reduction of the band and the occurrence of phase slip near the sidewall was verified by experiments on RBC [24,25], on the buckling of plates subjected to a compressional stress [26,27], and on Bénard-Marangoni convection [28]. However, this early work was mostly qualitative and for relatively large ǫ. Qualitative confirmation of a boundary-reduced wavenumber band was obtained also from numerical calculations for narrow RBC systems of finite length.…”

Section: Introductionmentioning

confidence: 99%

Boundary limitation of wave numbers in Taylor-vortex flow

Linek

Ahlers

1998

Phys. Rev. E

View full text Add to dashboard Cite

We report experimental results for a boundary-mediated wavenumber-adjustment mechanism and for a boundary-limited wavenumber-band of Taylor-vortex flow (TVF). The system consists of fluid contained between two concentric cylinders with the inner one rotating at an angular frequency Ω. As observed previously, the Eckhaus instability (a bulk instability) is observed and limits the stable wavenumber band when the system is terminated axially by two rigid, non-rotating plates. The band width is then of order ǫ 1/2 at small ǫ (ǫ ≡ Ω/Ωc − 1) and agrees well with calculations based on the equations of motion over a wide ǫ-range. When the cylinder axis is vertical and the upper liquid surface is free (i.e. an air-liquid interface), vortices can be generated or expelled at the free surface because there the phase of the structure is only weakly pinned. The band of wavenumbers over which Taylor-vortex flow exists is then more narrow than the stable band limited by the Eckhaus instability. At small ǫ the boundary-mediated band-width is linear in ǫ. These results are qualitatively consistent with theoretical predictions, but to our knowledge a quantitative calculation for TVF with a free surface does not exist.

show abstract

Régimes convectifs instationnaires dans l'air en cavité à grands facteurs d'aspect : résultats expérimentaux

Cited by 9 publications

References 6 publications

Apparatus for the study of Rayleigh–Bénard convection in gases under pressure

Apparatus for the study of Rayleigh–Bénard convection in gases under pressure

Rayleigh-Bénard convective structures in a cylindrical container

Boundary limitation of wave numbers in Taylor-vortex flow

Contact Info

Product

Resources

About