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Published on: April 30, 2018
Intermittency of temperature field in turbulent convection
1Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong.
Summary
Turbulent convection shows distinct temperature scaling behavior above and below the Bolgiano scale. Log-Poisson statistics accurately describe these exponents, revealing consistent intermittency across scales.
Area of Science:
- Fluid dynamics
- Geophysics
- Atmospheric science
Background:
- Turbulent convection is crucial in various natural systems, including Earth's atmosphere and oceans.
- Understanding temperature fluctuations and scaling laws is key to modeling these phenomena.
- The Bolgiano scale signifies a transition in the dynamics of stratified turbulence.
Purpose of the Study:
- To investigate the scaling behavior of temperature structure functions in turbulent convection.
- To analyze how this behavior differs across length scales relative to the Bolgiano scale.
- To determine the statistical properties governing temperature intermittency.
Main Methods:
- Analysis of temperature structure functions in turbulent convection.
- Application of log-Poisson statistics to describe scaling exponents.
- Comparison of intermittency parameters across different scale regimes.
Main Results:
- Temperature structure function scaling differs for length scales below and above the Bolgiano scale.
- Log-Poisson statistics effectively describe the exponents for both scale regimes.
- The intermittency parameter beta(T) remains consistent across scales and aligns with passive scalar field values.
Conclusions:
- The study confirms distinct scaling regimes in turbulent convection, demarcated by the Bolgiano scale.
- Log-Poisson statistics provide a robust framework for characterizing temperature intermittency.
- The findings support the theoretical framework involving thermal forcing and nonlinear advection in stratified turbulence.
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