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arXiv · 1409.3621

Influence of the spatial resolution on fine-scale features in DNS of turbulence generated by a single square grid

S. Laizet·J. Nedić·J. C. Vassilicos
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Abstract

We focus in this paper on the effect of the resolution of Direct Numerical Simulations (DNS) on the spatio-temporal development of the turbulence downstream of a single square grid. The aims of this study are to validate our numerical approach by comparing experimental and numerical one-point statistics downstream of a single square grid and then investigate how the resolution is impacting the dynamics of the flow. In particular, using the Q-R diagram, we focus on the interaction between the strain-rate and rotation tensors, the symmetric and skew-symmetric parts of the velocity gradient tensor respectively. We first show good agreement between our simulations and hot-wire experiment for one-point statistics on the centreline of the single square grid. Then, by analysing the shape of the Q-R diagram for various streamwise locations, we evaluate the ability of under-resolved DNS to capture the main features of the turbulence downstream of the single square grid.

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S. Laizet, J. Nedić, J. C. Vassilicos. 2014-09-11. Influence of the spatial resolution on fine-scale features in DNS of turbulence generated by a single square grid. https://doi.org/10.1080/10618562.2015.1058371

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