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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/2503.12558 |
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| _version_ | 1866910877889855488 |
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| author | Yu, ShuChang Shang, Jin Chen, YangRui Li, Ran Chen, Quan Yang, Hui Zheng, Hu Zhang, Jie |
| author_facet | Yu, ShuChang Shang, Jin Chen, YangRui Li, Ran Chen, Quan Yang, Hui Zheng, Hu Zhang, Jie |
| contents | This study used Speckle Visibility Spectroscopy to examine velocity fluctuations in a three-dimensional granular heap flow, where the mean velocity profile consists of a fast-flow surface layer and a creep layer beneath. The velocity spectra follow power-law scalings, $E(f) \propto f^α$, with $α\approx -0.85$ in the surface flow layer -- matching the Self-Organized Criticality (SOC) model with open boundaries ($α\approx -0.95$). In the creep layer, $α$ decreases with depth, reaching $α\approx -1.5$ at approximately 55 mean particle diameters, consistent with the SOC model with closed boundaries ($α\approx -1.58$). Analysis of the fluctuation velocity distributions offers additional insights into the microscopic origins of the spectrum's characteristics. These findings help resolve the long-standing puzzle of flow localization in gravity-driven granular flows despite a constant shear stress-to-pressure ratio throughout the material. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_12558 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Power Spectra of Velocity Fluctuations in Granular Heap Flow Yu, ShuChang Shang, Jin Chen, YangRui Li, Ran Chen, Quan Yang, Hui Zheng, Hu Zhang, Jie Soft Condensed Matter This study used Speckle Visibility Spectroscopy to examine velocity fluctuations in a three-dimensional granular heap flow, where the mean velocity profile consists of a fast-flow surface layer and a creep layer beneath. The velocity spectra follow power-law scalings, $E(f) \propto f^α$, with $α\approx -0.85$ in the surface flow layer -- matching the Self-Organized Criticality (SOC) model with open boundaries ($α\approx -0.95$). In the creep layer, $α$ decreases with depth, reaching $α\approx -1.5$ at approximately 55 mean particle diameters, consistent with the SOC model with closed boundaries ($α\approx -1.58$). Analysis of the fluctuation velocity distributions offers additional insights into the microscopic origins of the spectrum's characteristics. These findings help resolve the long-standing puzzle of flow localization in gravity-driven granular flows despite a constant shear stress-to-pressure ratio throughout the material. |
| title | Power Spectra of Velocity Fluctuations in Granular Heap Flow |
| topic | Soft Condensed Matter |
| url | https://arxiv.org/abs/2503.12558 |