Impact of the floating-point precision and interpolation scheme on the results of DNS of turbulence by pseudo-spectral codes

TL;DR

This study examines how floating-point precision and interpolation schemes affect DNS turbulence results, finding that precision has little impact while interpolation influences acceleration statistics and intermittency.

Contribution

It demonstrates that single precision is sufficient for DNS turbulence simulations, and highlights the significance of interpolation schemes on Lagrangian statistics.

Findings

No difference in statistical results across floating-point precisions.

Interpolation scheme affects acceleration PDF and intermittency.

Single precision enables higher Reynolds number simulations.

Abstract

In this paper we investigate the impact of the floating-point precision and interpolation scheme on the results of direct numerical simulations (DNS) of turbulence by pseudo-spectral codes. Three different types of floating-point precision configurations show no differences in the statistical results. This implies that single precision computations allow for increased Reynolds numbers due to the reduced amount of memory needed. The interpolation scheme for obtaining velocity values at particle positions has a noticeable impact on the Lagrangian acceleration statistics. A tri-cubic scheme results in a slightly broader acceleration probability density function than a tri-linear scheme. Furthermore the scaling behavior obtained by the cubic interpolation scheme exhibits a tendency towards a slightly increased degree of intermittency compared to the linear one.