Velocity and acceleration statistics in rapidly rotating Rayleigh–Bénard convection

Rajaei, Hadi; Alards, Kim M. J.; Kunnen, Rudie; Clercx, Hjh Herman

doi:10.1017/jfm.2018.751

Cited by 10 publications

(18 citation statements)

References 76 publications

(131 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moving down in Ro (or E) to the rotation-dominated range at Ro ≈ 0.1, Re is rapidly reduced. These results have been confirmed by Rajaei et al [99] using PTV, identifying the ratio Re hor /Re ver , i.e. the ratio of horizontal over vertical velocity fluctuations, as a good indicator of entering the rotation-dominated columnar range.…”

Section: Convection In Watersupporting

confidence: 75%

“…At the same time, the trick is to still be able to reliably provide Rayleigh numbers small enough to explore the rotation-dominated range; no simple task given that Ra ∼ H 3 [86]. That is [32,95]; King et al [94,96]; Niemela et al [38]; Weiss and Ahlers [46,97]; Cheng et al [40]; Cheng et al [44]; Lu et al [90]; Kunnen et al [33,45,98]; Rajaei et al [71]; Rajaei et al [99]; Shi et al [73]; Stevens et al [100]; Horn and Shishkina [101]; de Wit et al [87]; Yang et al [29] and Weiss et al [51].…”

Section: Convection In Watermentioning

confidence: 99%

“…Rajaei et al [99] have performed 3D PTV measurements in RRBC. In PTV one tracks the motion of individual tracer particles in time; by using multiple cameras 3D trajectories can be obtained.…”

Section: Inertial Wave Resonancementioning

confidence: 99%

See 2 more Smart Citations

The geostrophic regime of rapidly rotating turbulent convection

Kunnen

2021

Journal of Turbulence

Self Cite

View full text Add to dashboard Cite

Rotating Rayleigh-Bénard convection is a simple model system used to study the interplay of buoyant forcing and rotation. Many recent studies have focused on the geostrophic regime of turbulent rotating convection where the principal balance of forces is between the Coriolis force and the pressure gradient. This regime is believed to be representative of conditions in geophysical and astrophysical flows. We hope to be able to extrapolate findings from laboratory experiments and numerical simulations towards these large-scale natural flows. In this paper I sketch the phase diagram of the geostrophic regime of rotating convection, put experimental and numerical studies in their place in these diagrams and discuss the partitioning into subranges characterised by different flow structures and heat transfer scaling. I also discuss some complications faced by experimentalists, such as constraints on the dimensions of the convection cell, wall modes near the sidewall and centrifugal buoyancy.

show abstract

Section: Convection In Watersupporting

confidence: 75%

Section: Convection In Watermentioning

confidence: 99%

See 1 more Smart Citation

The geostrophic regime of rapidly rotating turbulent convection

Kunnen

2021

Journal of Turbulence

Self Cite

View full text Add to dashboard Cite

show abstract

“…square cuboid or cylinder) as well as by choice of boundary condition (no-slip or stress-free; zero-heat-flux or constant temperature). In contrast, experiments must resort to lateral confinement, where an upright cylinder is by far the most popular geometry [14][15][16][17][18][19]. In that case a parameter describing the geometry is required, for example the diameter-to-height aspect ratio Γ = D/H.…”

Section: Introductionmentioning

confidence: 99%

Turbulent rotating convection confined in a slender cylinder: The sidewall circulation

et al. 2020

Self Cite

View full text Add to dashboard Cite

Recent studies of rotating Rayleigh-Bénard convection at high rotation rates and strong thermal forcing have shown a significant discrepancy in total heat transport between experiments on a confined cylindrical domain on the one hand and simulations on a laterally unconfined periodic domain on the other. This paper addresses this discrepancy using direct numerical simulations on a cylindrical domain. An analysis of the flow field reveals a region of enhanced convection near the wall, the sidewall circulation. The sidewall circulation rotates slowly within the cylinder in anticyclonic direction. It has a convoluted structure, illustrated by mean flow fields in horizontal cross-sections of the flow where instantaneous snapshots are compensated for the orientation of the sidewall circulation before averaging. Through separate analysis of the sidewall region and the inner bulk flow, we find that for higher values of the thermal forcing the heat transport in the inner part of the cylindrical domain, outside the sidewall circulation region, coincides with the heat transport on the unconfined periodic domain. Thus the sidewall circulation accounts for the differences in heat transfer between the two considered domains, while in the bulk the turbulent heat flux is the same as that of a laterally unbounded periodic domain. Therefore, experiments, with their inherent confinement, can still provide turbulence akin to the unbounded domains of simulations, and at more extreme values of the governing parameters for thermal forcing and rotation. We also provide experimental evidence for the existence of the sidewall circulation that is in close agreement with the simulation results.

show abstract

“…Even if our setup is completely different we can make a parallel with two new studies about 3D rotating Rayleigh-Bénard Convection. Rajaei et al [31] recently published new results about the rotation dominated regime in rapidly rotating Rayleigh-Bénard convection. They found that the transition to the rotation dominated regime coincides with the suppression of vertical motions, the strong penetration of vortical plumes into the bulk and a reduced interaction of vortical plumes with their surroundings.…”

Section: Convective Heat Fluxmentioning

confidence: 99%

Numerical Study of Rotating Thermal Convection on a Hemisphere

Fischer

Bruneau

Kellay

2020

Fluids

View full text Add to dashboard Cite

Numerical simulations of rotating two-dimensional turbulent thermal convection on a hemisphere are presented in this paper. Previous experiments on a half soap bubble located on a heated plate have been used for studying thermal convection as well as the effects of rotation on a curved surface. Here, two different methods have been used to produce the rotation of the hemisphere: the classical rotation term added to the velocity equation, and a non-zero azimuthal velocity boundary condition. This latter method is more adapted to the soap bubble experiments. These two methods of forcing the rotation of the hemisphere induce different fluid dynamics. While the first method is classically used for describing rotating Rayleigh–Bénard convection experiments, the second method seems to be more adapted for describing rotating flows where a shear layer may be dominant. This is particularly the case where the fluid is not contained in a closed container and the rotation is imposed on only one side of it. Four different diagnostics have been used to compare the two methods: the Nusselt number, the effective computation of the convective heat flux, the velocity and temperature fluctuations root mean square (RMS) generation of vertically aligned vortex tubes (to evaluate the boundary layers) and the energy/enstrophy/temperature spectra/fluxes. We observe that the dynamics of the convective heat flux is strongly inhibited by high rotations for the two different forcing methods. Also, and contrary to classical three-dimensional rotating Rayleigh–Bénard convection experiments, almost no significant improvement of the convective heat flux has been observed when adding a rotation term in the velocity equation. However, moderate rotations induced by non-zero velocity boundary conditions induce a significant enhancement of the convective heat flux. This enhancement is closely related to the presence of a shear layer and to the thermal boundary layer just above the equator.

show abstract

Velocity and acceleration statistics in rapidly rotating Rayleigh–Bénard convection

Cited by 10 publications

References 76 publications

The geostrophic regime of rapidly rotating turbulent convection

The geostrophic regime of rapidly rotating turbulent convection

Turbulent rotating convection confined in a slender cylinder: The sidewall circulation

Numerical Study of Rotating Thermal Convection on a Hemisphere

Contact Info

Product

Resources

About