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Effects of lower floating-point precision on scale-resolving numerical simulations of turbulence

Karp M, Stanly R, Mukha T, Galimberti L, Toosi S, Song H, Dalcin L, Rezaeiravesh S, Jansson N, Markidis S, Parsani M, Bose S, Lele S, Schlatter P (2026)

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Publication Type: Journal article

Publication year: 2026

Journal

Book Volume: 549

Article Number: 114600

DOI: 10.1016/j.jcp.2025.114600

Abstract

Modern computing clusters offer specialized hardware for reduced-precision arithmetic, which can significantly speed up the time to solution. This is possible due to a decrease in data movement, as well as the ability to perform arithmetic operations at a faster rate. However, for high-fidelity simulations of turbulence, such as direct and large-eddy simulation, the impact of reduced precision on the computed solution and the resulting uncertainty across flow solvers and different flow cases has not been explored in detail, and limits the optimal utilization of new high-performance computing systems. In this work, the effect of reduced precision is studied using four diverse computational fluid dynamics (CFD) solvers (two incompressible, Neko and Simson, and two compressible, PadeLibs and SSDC) using four test cases: turbulent channel flow at Reτ=550 and higher, forced transition in a channel, flow over a cylinder at ReD=3900, and compressible flow over a wing section at Rec=50000. We observe that the flow physics are remarkably robust with respect to reductions in lower floating-point precision, and that often other forms of uncertainty, due to, for example, time averaging, often have a much larger impact on the computed result. Our results indicate that different terms in the Navier–Stokes equations can be computed to a lower floating-point accuracy without affecting the results. In particular, standard IEEE single precision can be used effectively for the entirety of the simulation, showing no significant discrepancies from double-precision results across the solvers and cases considered. Potential pitfalls are also discussed.

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How to cite

APA:

Karp, M., Stanly, R., Mukha, T., Galimberti, L., Toosi, S., Song, H.,... Schlatter, P. (2026). Effects of lower floating-point precision on scale-resolving numerical simulations of turbulence. Journal of Computational Physics, 549. https://doi.org/10.1016/j.jcp.2025.114600

MLA:

Karp, Martin, et al. "Effects of lower floating-point precision on scale-resolving numerical simulations of turbulence." Journal of Computational Physics 549 (2026).

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