Sie können Bookmarks mittels Listen verwalten, loggen Sie sich dafür bitte in Ihr SLUB Benutzerkonto ein.
Medientyp:
E-Artikel
Titel:
Grid-point and time-step requirements for direct numerical simulation and large-eddy simulation
Beteiligte:
Yang, Xiang I. A.;
Griffin, Kevin P.
Erschienen:
AIP Publishing, 2021
Erschienen in:Physics of Fluids
Sprache:
Englisch
DOI:
10.1063/5.0036515
ISSN:
1089-7666;
1070-6631
Entstehung:
Anmerkungen:
Beschreibung:
<jats:p>We revisit the grid-point requirement estimates in Choi and Moin [“Grid-point requirements for large eddy simulation: Chapman’s estimates revisited,” Phys. Fluids 24, 011702 (2012)] and establish more general grid-point requirements for direct numerical simulations (DNS) and large-eddy simulations (LES) of a spatially developing turbulent boundary layer. We show that by allowing the local grid spacing to scale with the local Kolmogorov length scale, the grid-point requirement for DNS of a spatially developing turbulent boundary layer is N∼ReLx2.05 rather than N∼ReLx2.64, as suggested by Choi and Moin, where N is the number of grid points and Lx is the length of the plate. In addition to the grid-point requirement, we estimate the time-step requirement for DNS and LES. We show that for a code that treats the convective term explicitly, the time steps required to get converged statistics are Nt∼ReLx/Rex06/7 for wall-modeled LES and Nt∼ReLx/Rex01/7 for wall-resolved LES and DNS (with different prefactors), where Rex0 is the inlet Reynolds number. The grid-point and time-step requirement estimates allow us to estimate the overall cost of DNS and LES. According to the present estimates, the costs of DNS, wall-resolved LES, and wall-modeled LES scale as ReLx2.91, ReLx2.72, and ReLx1.14, respectively.</jats:p>