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| Main Authors: | , , |
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| Format: | Preprint |
| Published: |
2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2512.11586 |
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| _version_ | 1866915936934559744 |
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| author | Ben-Shlomo, David Berkovich, Ronen Fattal, Eyal |
| author_facet | Ben-Shlomo, David Berkovich, Ronen Fattal, Eyal |
| contents | We investigate the validity of the Markovian assumption in modeling near-wall turbulence by analyzing the detachment of micron-sized particles from the viscous sublayer. By coupling direct numerical simulations with a fractional Ornstein-Uhlenbeck process, we demonstrate that while wall shear stress events follow Poissonian occurrence statistics, their internal dynamics exhibit strong temporal persistence (Hurst exponent $H \approx 0.84$), indicating non-Markovian memory. We reveal that the successful predictions of Markovian resuspension models stems from their free parameter acting as a phenomenological surrogate for flow memory. We further identify a critical regime transition governed by a wall shear stress events decay rate, $λ$. We identify a strong intermittency regime ($λ< 0.2$), where coherent structures exhibit extended temporal correlations that cannot be mimicked by white noise. Conversely, rapid decays ($λ> 0.2$) generate quasi-random fluctuations that justify the Markovian approximation. These findings offer a new perspective on the physical validity of classical stochastic modeling in wall-bounded flows. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_11586 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | On the Markovian assumption in near-wall turbulence: The case of particle resuspension Ben-Shlomo, David Berkovich, Ronen Fattal, Eyal Fluid Dynamics We investigate the validity of the Markovian assumption in modeling near-wall turbulence by analyzing the detachment of micron-sized particles from the viscous sublayer. By coupling direct numerical simulations with a fractional Ornstein-Uhlenbeck process, we demonstrate that while wall shear stress events follow Poissonian occurrence statistics, their internal dynamics exhibit strong temporal persistence (Hurst exponent $H \approx 0.84$), indicating non-Markovian memory. We reveal that the successful predictions of Markovian resuspension models stems from their free parameter acting as a phenomenological surrogate for flow memory. We further identify a critical regime transition governed by a wall shear stress events decay rate, $λ$. We identify a strong intermittency regime ($λ< 0.2$), where coherent structures exhibit extended temporal correlations that cannot be mimicked by white noise. Conversely, rapid decays ($λ> 0.2$) generate quasi-random fluctuations that justify the Markovian approximation. These findings offer a new perspective on the physical validity of classical stochastic modeling in wall-bounded flows. |
| title | On the Markovian assumption in near-wall turbulence: The case of particle resuspension |
| topic | Fluid Dynamics |
| url | https://arxiv.org/abs/2512.11586 |