Study on the resolution requirements for DNS in turbulent Rayleigh-Bénard convection

Kurzfassung

Two different recommendations by Gr"otzbach and Verzicco which are based on DNS that differ by about $5$ orders of magnitude lead to the assumption that the resolution requirements strongly depend on the turbulent sate of the flow. It is therefore envisaged to perform a number of direct simulations for Ra>10^5 and compare not only the Nusselt number but also the impact of the resolution on the statistics of the boundary layers as a function of Ra. For this purpose a set of numerical simulations in the range 3.5x10^5 <= Ra <= 2.31x10^8 is available, so that the grids can be precisely adapted to the desired resolution. Hence, not only global quantities, but also local properties of the flow can be compared, in order to have a sound basis for a comparison.