kth.sePublications KTH
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
An experimental study of 2D radial flow of a yield stress fluid between parallel disks
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Resources, Energy and Infrastructure.ORCID iD: 0000-0002-0958-7181
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics. Skanska Sweden AB.ORCID iD: 0000-0002-3981-447X
2019 (English)In: September 2-3, 2019, Helsinki. Nordic Grouting Symposium 2019, Helsinki: Nordic Grouting Symposium , 2019Conference paper, Published paper (Refereed)
Abstract [en]

During the design phase in rock grouting applications (e.g. for tunnels), analytical and numerical techniques based on inputs from the rock mass characterization and grout flow properties are used to estimate the grout spread. The design process is complicated by the fact that the exact geometry (network of fractures) within the rock mass is not completely known. In addition, the rheological flow properties of commonly used cement-based grouts are complex due to thixotropy and hydration. In such cases, simplified one-dimensional (1D) and two-dimensional 2D fracture geometries are used as a basis for the design solution. As for cement grouts, their rheological behavior is normally described by simplified constitutive laws e.g. the Bingham model.  Several  analytical solutions  for 1D channel flow and 2D radial flow of cement grouts have been presented in the literature describing the spread of grouts in fractures. Experimentally, only a limited amount of work has been carried out to study idealized yield stress fluid (YSF) flow between stationary parallel disks. The importance of such tests is that they facilitate the verification of analytical solutions and their limitations. Thus, in order to investigate in principle, the nature of 2D Bingham fluid  velocity profiles in radial  flow, we carried out  for apparently the first time  ultrasound velocimetry measurements  within the constraints of an experimental model. The  radial  flow region was formed by the gap (aperture) between two parallel acrylic glass (Plexiglas) disks, each with a diameter of 1 meter and a thickness of 25 mm. The disk separation was attained from a variable height metallic spacer configuration. Ultrasound velocity profiling (UVP) was used for flow visualization through the measurement of velocity profiles of a model yield stress fluid (Carbopol) at different radial positions. The results are a comparison of the measured velocity profiles with those from analytical solutions. Of particular interest is the plug-flow region of the radial velocity profiles along the radial length (diameter) of the parallel disks. The current observations show a distinct plug region, coupled with wall slip effects for the Carbopol model YSF fluid that was used. The theoretically predicted velocity profiles are lower than  the measured ones, however within a reasonably similar magnitude range. The main discrepancies between the theoretical predictions and measured data are then discussed. Future studies would then be targeted at improving the current experimental setup, for detailed measurements of the  plug-flow region along the radial length, which remains a generally challenging issue for studies on YSFs and more specifically for rock grouting design.  Moreover,  considering  roughened walls to significantly reduce wall slip  that was  present in the current study will also be part of the project’s continuation.

Place, publisher, year, edition, pages
Helsinki: Nordic Grouting Symposium , 2019.
Keywords [en]
Rock Grouting, Cement grouts, Yield Stress Fluid, Radial flow, Plug-flow region
National Category
Geotechnical Engineering and Engineering Geology
Research subject
Civil and Architectural Engineering
Identifiers
URN: urn:nbn:se:kth:diva-258421Scopus ID: 2-s2.0-85079330266OAI: oai:DiVA.org:kth-258421DiVA, id: diva2:1350017
Conference
ISRM 9th Nordic Grouting Symposium, NGS 2019, Helsinki, 2-3 September 2019
Funder
Rock Engineering Research Foundation (BeFo), 399
Note

QC 20191011

Available from: 2019-09-10 Created: 2019-09-10 Last updated: 2025-02-07Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

ScopusFulltext

Authority records

Shamu, Tafadzwa JohnZou, LiangchaoHåkansson, Ulf

Search in DiVA

By author/editor
Shamu, Tafadzwa JohnZou, LiangchaoHåkansson, Ulf
By organisation
Soil and Rock MechanicsResources, Energy and Infrastructure
Geotechnical Engineering and Engineering Geology

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 238 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf