Abstract
We carry out direct numerical simulations of horizontally or vertically vibrated Rayleigh–Bénard (RB) convection over a wide range of Rayleigh number and dimensionless vibration frequency at fixed Prandtl number and dimensionless vibration amplitude . It is shown that the global heat transport (measured by the Nusselt number ) is close to the value of standard RB convection in buoyancy-dominant regime at small , whereas it is significantly enhanced by horizontal vibration or suppressed by vertical vibration in the vibration-dominant regime at large . The division between the two regimes yields a critical vibration frequency , which indicates the onset of vibration-induced enhancement or reduction. The values of are obtained based on the fitting between the numerical data and our proposed crossover functions. The dependence of on is then studied. It is found that the fitted critical frequency exhibits two close scaling relations: in horizontally vibrated RB convection and in vertically vibrated cases. Moreover, based on the competition of the kinetic energy production between buoyancy-dominant and vibration-dominant regimes, a physical model is proposed to predict the scaling behavior between and , i.e., , which agrees well with the measured scaling exponents of our numerical data.
- Received 27 April 2023
- Accepted 3 October 2023
DOI:https://doi.org/10.1103/PhysRevFluids.8.113501
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