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arXiv · 2607.25185

Turbulent Flame Speed Can Increase under Curvature Smoothing

Hung V. Tran·Jack Xin·Yifeng Yu
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Abstract

Curvature effects are expected to smooth flame-front wrinkles and thereby reduce turbulent flame speed. We construct a smooth three-dimensional periodic shear flow for which introducing Markstein curvature diffusivity instead increases the effective flame speed predicted by the level-set G-equation. This gives the first counterexample, within this model, to monotone slowdown under curvature smoothing and contrasts with the rigorous monotonicity result for two-dimensional shear flows. The example reveals a genuinely multidimensional mechanism in which local curvature smoothing can enhance, rather than suppress, large-scale front propagation.

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Hung V. Tran, Jack Xin, Yifeng Yu. 2026-07-28. Turbulent Flame Speed Can Increase under Curvature Smoothing. https://arxiv.org/abs/2607.25185

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