Numerical Study of Effect of Polymer Additives on Heat Transport in Turbulent Rayleigh- Bénard Convection

Abstract:

In this study, the Reynolds-Averaged-Navier-Stokes (RANS) model combined with the Cross Viscosity Equation is used, applied to the soft turbulence regime (Ra =5×105~4×107) and hard turbulence regime (Ra>4×107) of Rayleigh-Bénard convection (RBC). The relation curves between heat transport (Nusselt number) and other parameters, as well as flow pattern changes of RBC are obtained for the cases with different Rayleigh number and concentration of the polymer additive. The simulations show that the presence of polymer additive can lead to an enhancement of the heat transfer with larger effect in the hard turbulence regime than those in the soft turbulence regime. It is also shown that in the soft turbulence regime the reversal cycles are shorter than in hard turbulence regime. The symmetric vortices in the diagonal corner of enclosed space shrink and the velocities of large-scale circulation (LSC) increase accordingly.

• Periodical: Advanced Materials Research (Volumes 472-475)
• Pages: 1283-1288
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.472-475.1283
• Online since: February 2012
• Authors: Chen Hui Zheng, Chang Feng Li, Hua Hong Jiang
• Keywords: Cross Viscosity Equation, Heat Transport, Rayleigh-Bénard Convection (RBC), Reynolds-Averaged-Navier-Stokes (RANS), Turbulence

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