Flow behavior and heat transfer characteristics in Rayleigh-Bénard laminar convection with fluid-particle interaction

Abstract

The present study experimentally and numerically investigates the Rayleigh-Bénard (R-B) laminar convection of a Newtonian fluid in a square cavity heated from the bottom wall at the initial conditions of constant temperature field and stationary flow field over the range of Rayleigh number Ra ≤ 4 × 104. The effect of a freely-moving particle in the cavity on the flow pattern and heat transfer characteristics is discussed. When the stable multi-stability patterns coexist, i.e. Ra is beyond a certain critical value, the final flow pattern can be manipulated by adjusting the initial position of the particle. The bicellular mode is established if the particle is located at the bottom center of the cavity while the unicellular mode is established if the particle is away from the center. The present results demonstrate that at the same Ra, the thermal performance is mainly determined by the flow pattern but not the presence of a particle. However, one can control the final flow pattern for R-B convection by adjusting the initial position of the particle, which consequently determines the thermal performance.