Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Characterization of Flow Structures Induced by Highly Rough Surface Using Particle Image Velocimetry, Proper Orthogonal Decomposition and Velocity Correlations
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik. (Strömningslära)ORCID-id: 0000-0001-9426-2375
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik. (Strömningslära)ORCID-id: 0000-0002-4916-9566
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.ORCID-id: 0000-0002-8360-9051
Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik. Vattenfall Research and Development, Älvkarleby.
Vise andre og tillknytning
2018 (engelsk)Inngår i: Engineering, ISSN 1947-3931, Vol. 10, s. 399-416Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

High Reynolds number flow inside a channel of rectangular cross section is examined using Particle Image Velocimetry. One wall of the channel has been replaced with a surface of a roughness representative to that of real hydropower tunnels, i.e. a random terrain with roughness dimensions typically in the range of ≈10% - 20% of the channels hydraulic radius. The rest of the channel walls can be considered smooth. The rough surface was captured from an existing blasted rock tunnel using high resolution laser scanning and scaled to 1:10. For quantification of the size of the largest flow structures, integral length scales are derived from the auto-correlation functions of the temporally averaged velocity. Additionally, Proper Orthogonal Decomposition (POD) and higher-order statistics are applied to the instantaneous snapshots of the velocity fluctuations. The results show a high spatial heterogeneity of the velocity and other flow characteristics in vicinity of the rough surface, putting outer similarity treatment into jeopardy. Roughness effects are not confined to the vicinity of the rough surface but can be seen in the outer flow throughout the channel, indicating a different behavior than postulated by Townsend’s similarity hypothesis. The effects on the flow structures vary depending on the shape and size of the roughness elements leading to a high spatial dependence of the flow above the rough surface. Hence, any spatial averaging, e.g. assuming a characteristic sand grain roughness factor, for determining local flow parameters becomes less applicable in this case.

sted, utgiver, år, opplag, sider
Scientific Research Publishing, 2018. Vol. 10, s. 399-416
Emneord [en]
CFD, Validation, Hydraulic Roughness, PIV, Hydropower
HSV kategori
Forskningsprogram
Strömningslära
Identifikatorer
URN: urn:nbn:se:ltu:diva-71097DOI: 10.4236/eng.2018.107028OAI: oai:DiVA.org:ltu-71097DiVA, id: diva2:1253280
Merknad

Validerad;2020;Nivå 1;2020-01-07 (marisr)

Tilgjengelig fra: 2018-10-04 Laget: 2018-10-04 Sist oppdatert: 2020-01-07bibliografisk kontrollert
Inngår i avhandling
1. Modelling flow over rough surfaces in hydropower waterways
Åpne denne publikasjonen i ny fane eller vindu >>Modelling flow over rough surfaces in hydropower waterways
2018 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Luleå: Luleå University of Technology, 2018
Serie
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
HSV kategori
Forskningsprogram
Strömningslära
Identifikatorer
urn:nbn:se:ltu:diva-71104 (URN)978-91-7790-224-9 (ISBN)978-91-7790-225-6 (ISBN)
Disputas
2018-11-23, E632, Luleå tekniska universitet, Luleå, 10:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2018-10-08 Laget: 2018-10-04 Sist oppdatert: 2018-11-21bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekst

Personposter BETA

Andersson, L. RobinLarsson, SofiaHellström, J. Gunnar I.Andreasson, PatrikAndersson, Anders G.Lundström, Staffan

Søk i DiVA

Av forfatter/redaktør
Andersson, L. RobinLarsson, SofiaHellström, J. Gunnar I.Andreasson, PatrikAndersson, Anders G.Lundström, Staffan
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 290 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf