hig.sePublikasjoner
Endre søk

Referera
Referensformat
• apa
• harvard-cite-them-right
• ieee
• modern-language-association-8th-edition
• vancouver
• Annet format
Fler format
Språk
• sv-SE
• en-GB
• en-US
• fi-FI
• nn-NO
• nn-NB
• de-DE
• Annet språk
Fler språk
Utmatningsformat
• html
• text
• asciidoc
• rtf
Energiförluster i vattenkraftstunnlar och älvsträckor: Hur påverkas Manningtalet när skrovlighetens geometri är stor i förhållande till tvärsektionens geometri?
Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för bygg- energi- och miljöteknik, Energisystem.
2018 (svensk)Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
##### Hållbar utveckling
Uppsatsen/examensarbetet har inslag av hållbar utveckling enligt högskolans kriterier
##### Abstract [en]

When water travels along a channel is the bottom which the water is in direct contact with, defined by a coefficient named

Manning’s coefficient of friction. This coefficient explains the roughness of the channel bed. A rough surface equals a low Manning’s coefficient. The purpose of this thesis is to study how Manning’s coefficient differs when different waterflows and depths is obtained. The Manning equation is depend-ent on using a constant Manning’s coefficient based on experience and tables. The experience in the line of business knows that the coefficient holds a different value in channels with similar bathymetry and different flow conditions, and the thesis will cover these questions.

At Vattenfall Research & Development in Älvkarleby, a flume made for fluid me-chanic experiments has been built, which is perfectly suitable for the experiments for this thesis. The flume has a roughness that has been programmed mathematically with a purpose of looking like a real channel bed or a blasted rock-tunnel. This is where all the measurements were made.

The measurements were made in totally 14 cross-sections with a few different flows and depths. The depth was controlled by a hatchway downstream the flume and the flow were controlled by the pumps. Depending on which setting the hatchway ob-tained measurements between 1.6 l/s to 280 l/s were made. The different settings that were used for the hatch was 100 %, 85 %, 75 %, 60 % and 30 % open hatch. The most obvious results appeared when the hatch was 100 % open, since the differ-ence in depth between each cross-section was large and the faults in the equipment

weren’t that important. 30 % open hatch generated such calm flow and a deep depth, so the errors were too big to include in the report. These different flow conditions were used to gain a big variation and accuracy, with the purpose of getting as good result as possible.

The measurements show that for every hatch-setting, the Manning coefficient gets lower when a lower depth and flow are held. If the results are plotted from all the hatch-settings, especially 100 % open in a graph with the Manning coefficient as a function of the flow, the results follow an obvious shape with a trend where the Man-ning coefficient reduces with lower flows. The same thing with the depth. Shallower depth equals lower Manning coefficient. This is because of the roughness elements that has a bigger part of the entire cross-sectional area, so that a bigger part of the cross-sectional area is affected by phenomenon caused by the roughness elements.

Key words: Manning’s coefficient,

streaming losses, energy losses, Vattenfall

2018. , s. 27
##### Emneord [sv]
Manningtal, Strömningsförluster, Energiförluster, Vattenfall
##### Identifikatorer
OAI: oai:DiVA.org:hig-27333DiVA, id: diva2:1223169
Vattenfall R&D
Energy systems
##### Utdanningsprogram
Energy systems – bachelor’s programme (in eng)
##### Examiner
Tilgjengelig fra: 2018-06-25 Laget: 2018-06-25 Sist oppdatert: 2018-06-25bibliografisk kontrollert

#### Open Access i DiVA

fulltext(987 kB)134 nedlastinger
##### Filinformasjon
Fil FULLTEXT01.pdfFilstørrelse 987 kBChecksum SHA-512
076f4061a6560c0b41faaf7ab328ce8f5962edc0ebcc0f7ab0dfd0bd1d194cd74434e2a874830330fd250f445f8c5d09dc497041ff0e761b62955f1ac9220990
Type fulltextMimetype application/pdf

Myhr, Hampus

#### Søk utenfor DiVA

Totalt: 134 nedlastinger
Antall nedlastinger er summen av alle nedlastinger av alle fulltekster. Det kan for eksempel være tidligere versjoner som er ikke lenger tilgjengelige
urn-nbn

#### Altmetric

urn-nbn
Totalt: 130 treff

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