Modeling the impact of natural roughness of tension joints on heat transport.
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| Title: | Modeling the impact of natural roughness of tension joints on heat transport. |
|---|---|
| Authors: | Nigon, Benoit1 (AUTHOR) nigonben@univ-rouen.fr, Pascal, Christophe2 (AUTHOR), Englert, Andreas1,2 (AUTHOR) |
| Source: | Geothermics. Dec2024, Vol. 124, pN.PAG-N.PAG. 1p. |
| Subjects: | Flow velocity, Fluid flow, Moments method (Statistics), LIDAR, Velocity |
| Abstract: | • First study on real tension joint fracture with a characteristic plumose structure, scanned using LiDAR technology. • Hydraulic aperture and the longitudinal component of the velocity vector decrease with increasing roughness. • Local variation of heat transport parameters is controlled by fracture roughness. • Different heat transport regimes identified, based on fracture aperture and roughness. The understanding of heat transport in fractures is crucial for mining geothermal systems. Studies of heat transport in natural fractures at scales comprised between those of laboratory experiments and those of field tracer tests are seldom. To bridge the gap, a joint surface with characteristic plumose was scanned in the field using LiDAR technology. The scanned surface was used to build a numerical model of mode 1 fracture. Fluid flow and heat transport were modeled solving the steady-state Stokes equation and assuming Fourier transport, respectively. We considered three different fracture apertures and varied systematically roughness in order to investigate the impact of plumose on fluid and heat transport. The 3D velocity flow fields were characterized by mean hydraulic aperture and by statistics on the directional components of the velocity vector. The method of temporal moments was used to extract first and second moments from temperature breakthrough curves. Heat transport parameters (local and macroscopic) were calculated from first and second moments. We show that hydraulic aperture and the longitudinal component of the velocity vector decrease with increasing roughness. The local variation of heat transport parameters is controlled by fracture roughness. For the macroscopic transport parameters, several transport regimes were identified. At low fracture aperture (i.e. 1 mm), conductive regime dominates heat transport in agreement with low Péclet numbers. In this case, fracture roughness affects the transport parameters via the loss of hydraulic aperture. With higher aperture (i.e. 3 mm) geometrical dispersion regime is dominant, roughness controlling the amplitude of transport parameters. At 5 mm aperture, transition from geometrical to Taylor dispersion occurs and the roughness tends to decrease dispersion and dispersivity according to the mean flow velocity. [ABSTRACT FROM AUTHOR] |
| Copyright of Geothermics is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 179501886 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Modeling the impact of natural roughness of tension joints on heat transport. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Nigon%2C+Benoit%22">Nigon, Benoit</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> nigonben@univ-rouen.fr</i><br /><searchLink fieldCode="AR" term="%22Pascal%2C+Christophe%22">Pascal, Christophe</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Englert%2C+Andreas%22">Englert, Andreas</searchLink><relatesTo>1,2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Geothermics%22">Geothermics</searchLink>. Dec2024, Vol. 124, pN.PAG-N.PAG. 1p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Flow+velocity%22">Flow velocity</searchLink><br /><searchLink fieldCode="DE" term="%22Fluid+flow%22">Fluid flow</searchLink><br /><searchLink fieldCode="DE" term="%22Moments+method+%28Statistics%29%22">Moments method (Statistics)</searchLink><br /><searchLink fieldCode="DE" term="%22LIDAR%22">LIDAR</searchLink><br /><searchLink fieldCode="DE" term="%22Velocity%22">Velocity</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: • First study on real tension joint fracture with a characteristic plumose structure, scanned using LiDAR technology. • Hydraulic aperture and the longitudinal component of the velocity vector decrease with increasing roughness. • Local variation of heat transport parameters is controlled by fracture roughness. • Different heat transport regimes identified, based on fracture aperture and roughness. The understanding of heat transport in fractures is crucial for mining geothermal systems. Studies of heat transport in natural fractures at scales comprised between those of laboratory experiments and those of field tracer tests are seldom. To bridge the gap, a joint surface with characteristic plumose was scanned in the field using LiDAR technology. The scanned surface was used to build a numerical model of mode 1 fracture. Fluid flow and heat transport were modeled solving the steady-state Stokes equation and assuming Fourier transport, respectively. We considered three different fracture apertures and varied systematically roughness in order to investigate the impact of plumose on fluid and heat transport. The 3D velocity flow fields were characterized by mean hydraulic aperture and by statistics on the directional components of the velocity vector. The method of temporal moments was used to extract first and second moments from temperature breakthrough curves. Heat transport parameters (local and macroscopic) were calculated from first and second moments. We show that hydraulic aperture and the longitudinal component of the velocity vector decrease with increasing roughness. The local variation of heat transport parameters is controlled by fracture roughness. For the macroscopic transport parameters, several transport regimes were identified. At low fracture aperture (i.e. 1 mm), conductive regime dominates heat transport in agreement with low Péclet numbers. In this case, fracture roughness affects the transport parameters via the loss of hydraulic aperture. With higher aperture (i.e. 3 mm) geometrical dispersion regime is dominant, roughness controlling the amplitude of transport parameters. At 5 mm aperture, transition from geometrical to Taylor dispersion occurs and the roughness tends to decrease dispersion and dispersivity according to the mean flow velocity. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Geothermics is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.geothermics.2024.103145 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 1 StartPage: N.PAG Subjects: – SubjectFull: Flow velocity Type: general – SubjectFull: Fluid flow Type: general – SubjectFull: Moments method (Statistics) Type: general – SubjectFull: LIDAR Type: general – SubjectFull: Velocity Type: general Titles: – TitleFull: Modeling the impact of natural roughness of tension joints on heat transport. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Nigon, Benoit – PersonEntity: Name: NameFull: Pascal, Christophe – PersonEntity: Name: NameFull: Englert, Andreas IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 12 Text: Dec2024 Type: published Y: 2024 Identifiers: – Type: issn-print Value: 03756505 Numbering: – Type: volume Value: 124 Titles: – TitleFull: Geothermics Type: main |
| ResultId | 1 |