In:
Geoscientific Model Development, Copernicus GmbH, Vol. 11, No. 10 ( 2018-10-10), p. 4069-4084
Abstract:
Abstract. Aliasing errors arise in the multiplication of partial sums, such as those
encountered when numerically solving the Navier–Stokes equations, and can be
detrimental to the accuracy of a numerical solution. In this work, a
performance and cost analysis is proposed for widely used dealiasing schemes in
large-eddy simulation, focusing on a neutrally stratified, pressure-driven
atmospheric boundary-layer flow. Specifically, the exact 3∕2 rule, the
Fourier truncation method, and a high-order Fourier smoothing method are
intercompared. Tests are performed within a newly developed mixed pseudo-spectral finite differences large-eddy simulation code, parallelized
using a two-dimensional pencil decomposition. A series of simulations are
performed at varying resolution, and key flow statistics are intercompared
among the considered runs and dealiasing schemes. The three dealiasing methods compare well in terms of first- and second-order
statistics for the considered cases, with modest local departures that decrease
as the grid stencil is reduced. Computed velocity spectra using the 3∕2 rule and
the FS method are in good agreement, whereas the FT method yields a spurious energy
redistribution across wavenumbers that compromises both the energy-containing and
inertial sublayer trends. The main advantage of the FS and FT methods when compared to
the 3∕2 rule is a notable reduction in computational cost, with larger savings
as the resolution is increased (15 % for a resolution of 1283, up to a theoretical 30 % for a resolution of
20483).
Type of Medium:
Online Resource
ISSN:
1991-9603
DOI:
10.5194/gmd-11-4069-2018
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2456725-5
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