Effect of fluid-particle interaction on 2D Rayleigh-Bénard laminar convection of a temperature-sensitive magnetic fluid

Abstract

Rayleigh-Bénard (R–B) laminar convection of a temperature-sensitive magnetic fluid (TSMF) with an immersed nonmagnetic particle in a square cavity heated from the bottom and subject to an external magnetic field is investigated experimentally and numerically, which restricts to the initial constant temperature and stationary flow fields with perfect thermal insulated wall condition. The flow and particle behaviors as well as the heat transfer characteristic are examined at different Ra (Ra < 4 × 104) and Ram (Ram = 0, 1.89 × 108, and 3.14 × 108). The magnetic field slightly precipitates the onset of convection and the transition of the flow pattern. The particle may influence the early flow development and the final flow pattern, depending on the initial location of the particle, Ra, and Ram. Over certain ranges of the parameters, the particle stabilizes the flow by shifting the higher flow mode (bicellular) to the lower one (unicellular) and improves the heat transfer performance. The numerical results confirm the experimental findings and provide more detailed behaviors of the flow and temperature fields as well as the particle.