Heat transfer & large-scale dynamics in turbulent Rayleigh-Bénard convection
نویسندگان
چکیده
The progress in our understanding of several aspects of turbulent Rayleigh-Bénard convection is reviewed. The focus is on the question of how the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number Pr, and on how the thicknesses of the thermal and the kinetic boundary layers scale with Ra and Pr. Non-Oberbeck-Boussinesq effects and the dynamics of the large-scale convection-roll are addressed as well. The review ends with a list of challenges for future research on the turbulent Rayleigh-Bénard system.
منابع مشابه
Heat transfer and large scale dynamics in turbulent Rayleigh-Bénard convection
The progress in our understanding of several aspects of turbulent Rayleigh-Bénard convection is reviewed. The focus is on the question of how the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number Pr, and on how the thicknesses of the thermal and the kinetic boundary layers scale with Ra and Pr. Non-Oberbeck-Boussinesq effects and the dynamics of the ...
متن کاملTemperature statistics in turbulent Rayleigh–Bénard convection
Rayleigh–Bénard (RB) convection in the turbulent regime is studied using statistical methods. Exact evolution equations for the probability density function of temperature and velocity are derived from first principles within the framework of the Lundgren–Monin–Novikov hierarchy known from homogeneous isotropic turbulence. The unclosed terms arising in the form of conditional averages are estim...
متن کاملOptimal Prandtl number for heat transfer in rotating Rayleigh–Bénard convection
Numerical data for the heat transfer as a function of the Prandtl (Pr) and Rossby (Ro) numbers in turbulent rotating Rayleigh–Bénard convection are presented for Rayleigh number Ra = 108. When Ro is fixed, the heat transfer enhancement with respect to the non-rotating value shows a maximum as a function of Pr. This maximum is due to the reduced effect of Ekman pumping when Pr becomes too small ...
متن کاملOn the nature of fluctuations in turbulent Rayleigh–Bénard convection at large Prandtl numbers
We report experimental results for the power spectra, variance, skewness and kurtosis of temperature fluctuations in turbulent Rayleigh–Bénard convection (RBC) of a fluid with Prandtl number Pr= 12.3 in cylindrical samples with aspect ratios Γ (diameter D over height L) of 0.50 and 1.00. The measurements were primarily for the radial positions ξ = 1− r/(D/2)= 1.00 and ξ = 0.063. In both cases, ...
متن کاملScaling laws in turbulent Rayleigh-Bénard convection under different geometry
A systematic study of turbulent Rayleigh-Bénard convection is carried out in two horizontal cylindrical cells of different lengths filled with water. Global heat transport and local temperature and velocity measurements are made over varying Rayleigh numbers Ra. The scaling behavior of the measured Nusselt number Nu(Ra) and the Reynolds number Re(Ra) associated with the large-scale circulation ...
متن کامل