Wave number selection in Rayleigh-Bénard convection: A numerical study

1982 ◽  
Vol 5 (1) ◽  
pp. 75-82 ◽  
Author(s):  
M.C. Cross ◽  
P.C. Hohenberg ◽  
S.A. Safran
2012 ◽  
Vol 472-475 ◽  
pp. 1283-1288 ◽  
Author(s):  
Chen Hui Zheng ◽  
Chang Feng Li ◽  
Hua Hong Jiang

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.


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