Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour
Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained tractio...
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sg-ntu-dr.10356-897372020-03-07T11:43:33Z Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour Lee, Cheng-Hsien Low, Ying Min Chiew, Yee-Meng School of Civil and Environmental Engineering Rheology And Fluid Dynamics DRNTU::Engineering::Civil engineering Sediment Transport Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results. Published version 2018-12-20T09:10:53Z 2019-12-06T17:32:19Z 2018-12-20T09:10:53Z 2019-12-06T17:32:19Z 2016 Journal Article Lee, C.-H., Low, Y. M., & Chiew, Y.-M. (2016). Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour. Physics of Fluids, 28(5), 053305-. doi:10.1063/1.4948987 1070-6631 https://hdl.handle.net/10356/89737 http://hdl.handle.net/10220/47138 10.1063/1.4948987 en Physics of Fluids © 2016 The Author(s) (Published by AIP). This paper was published in Physics of Fluids and is made available as an electronic reprint (preprint) with permission of The Author(s) (Published by AIP). The published version is available at: [http://dx.doi.org/10.1063/1.4948987]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. 23 p. application/pdf |
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Rheology And Fluid Dynamics DRNTU::Engineering::Civil engineering Sediment Transport Lee, Cheng-Hsien Low, Ying Min Chiew, Yee-Meng Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
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Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results. |
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School of Civil and Environmental Engineering |
author_facet |
School of Civil and Environmental Engineering Lee, Cheng-Hsien Low, Ying Min Chiew, Yee-Meng |
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Article |
author |
Lee, Cheng-Hsien Low, Ying Min Chiew, Yee-Meng |
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Lee, Cheng-Hsien |
title |
Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
title_short |
Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
title_full |
Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
title_fullStr |
Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
title_full_unstemmed |
Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
title_sort |
multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour |
publishDate |
2018 |
url |
https://hdl.handle.net/10356/89737 http://hdl.handle.net/10220/47138 |
_version_ |
1681035155666370560 |