Abstract
Well-resolved direct numerical simulations of 2D Rayleigh-Bénard convection in a porous medium are presented for Rayleigh numbers which reveal that, contrary to previous indications, the linear classical scaling for the Nusselt number, , is attained asymptotically. The flow dynamics are analyzed, and the interior of the vigorously convecting system is shown to be increasingly well described as by a simple columnar “heat-exchanger” model with a single horizontal wave number and a linear background temperature field. The numerical results are approximately fitted by .
- Received 8 February 2012
DOI:https://doi.org/10.1103/PhysRevLett.108.224503
© 2012 American Physical Society