Convergence rate of individual and global quantities in direct numerical simulations

Cédric Flageul (1) , Iztok Tiselj (1)

1 IJS - Jozef Stefan Institute [Ljubljana]

Typical individual quantities in Direct Numerical Simulations of statistically steady flows are converging at a rate of 1/√ T , where T is the averaging time of the simulation. However, global quantities that represent integral momentum balance in the computational domain can exhibit a faster convergence rate of 1/T. This faster convergence rate is analysed and explained. Theoretical predictions are supported with a Direct Numerical Simulation.

Mots clés: Direct Numerical Simulation; Uncertainty Quantification; Sampling Error

Domaines: Mécanique des fluides [physics.class-ph]

Cédric Flageul, Iztok Tiselj. Convergence rate of individual and global quantities in direct numerical simulations. Physics of Fluids, 2018, 30 (11), ⟨10.1063/1.5052696⟩. ⟨hal-01929582⟩