Dynamics and Statistics of Reorientations of Large-Scale Circulation in Turbulent Rotating Rayleigh-Bénard Convection

Abstract

We present a direct numerical simulation to investigate the dynamics and statistics of reorientations of large-scale circulation (LSC) in turbulent rotating Rayleigh-Bénard convection (RRBC) for air ($Pr=0.7$) contained in a cylindrical cell with unit aspect ratio. A wide range of rotation rates ($0\le R{o}^{-1}\le 30$) is considered for two different Rayleigh numbers $Ra=2\times 10^6$ and $2\times 10^7$. Using the Fourier mode analysis of time series data obtained from the different probes placed in the azimuthal direction of the container at the mid-plane, the orientation and associated dynamics of LSC are characterized. The amplitude of the first Fourier mode quantifies the strength of LSC and its phase ${\Phi }_1$ gives the information of the azimuthal orientation of LSC. Based on the energy contained in the Fourier modes different flow regimes are identified as the rotation rate is varied for a given Rayleigh number. LSC structure is observed in the low rotation regime ( $R{o}^{-1}\lesssim 1$). A strong correlation between the orientation of LSC structure and the heat transfer and boundary layer dynamics is observed. In the LSC regime, the dissipation rates follow the log-normal behaviour, while at higher rotation rates, a clear departure from log-normality is noticed. Different types of reorientations, namely, rotation-led, cessation-led, partial and complete reversal are identified. The distribution of change in orientation of LSC follows a power law behaviour as $P(|\Delta {\Phi }_1|)\propto |\Delta {\Phi }_1{|}^{-m}$, with the exponent $m\approx 3.7$. In addition, the statistics of time interval between successive reorientations follow a Poisson distribution. These observations are in good agreement with earlier experimental results.

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References in corpus (23)

• Power laws, Pareto distributions and Zipf's law
• Large scale dynamics in turbulent Rayleigh-Benard convection
• Scaling in thermal convection: A unifying theory
• Radial boundary layer structure and Nusselt number in Rayleigh-Benard convection
• Flow reversals in thermally driven turbulence
• Rotations and cessations of the large-scale circulation in turbulent Rayleigh-Benard convection
• Orientation changes of the large-scale circulation in turbulent Rayleigh-Benard convection
• Plume motion and large-scale circulation in a cylindrical Rayleigh-Bénard cell
• Flow reversals in turbulent convection via vortex reconnections
• Dynamics and symmetries of flow reversals in turbulent convection
• Origin of the Temperature Oscillation in Turbulent Thermal Convection
• Fine-scale statistics of temperature and its derivatives in convective turbulence
• Dynamics of reorientations and reversals of large scale flow in Rayleigh-Benard convection
• Complexity of viscous dissipation in turbulent thermal convection
• Statistics and geometry of passive scalars in turbulence
• Horizontal Structures of Velocity and Temperature Boundary Layers in 2D Numerical Turbulent Rayleigh-Bénard Convection
• Flow reversals in turbulent convection with free-slip walls
• Effect of Plumes on Measuring the Large Scale Circulation in Turbulent Rayleigh-Bénard Convection
• Breakdown of the large-scale wind in Γ=1/2 rotating Rayleigh-Bénard flow
• Similarity model for corner roll in turbulent Rayleigh-Benard convection
• Extreme dissipation event due to plume collision in a turbulent convection cell
• Helicity of mean and turbulent flow with coherent structures in Rayleigh-Benard convective cell
• Energy Fluxes during Dynamo Reversals

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