Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Experimental study of passive scalar mixing in swirling jet flows
KTH, Skolan för teknikvetenskap (SCI), Mekanik.ORCID-id: 0000-0002-1663-3553
2006 (Engelska)Licentiatavhandling, monografi (Övrigt vetenskapligt)
Abstract [en]

Despite its importance in various industrial applications there is still a lack of experimental studies on the dynamic and thermal field of swirling jets in the near-field region. The present study is an attempt to close this lack and provide new insights on the effect of rotation on the turbulent mixing of a passive scalar, on turbulence (joint) statistics as well as the turbulence structure.

Swirl is known to increase the spreading of free turbulent jets and hence to entrain more ambient fluid. Contrary to previous experiments, which leave traces of the swirl generating method especially in the near-field, the swirl was imparted by discharging a slightly heated air flow from an axially rotating and thermally insulated pipe (6 m long, diameter 60 mm). This gives well-defined axisymmetric streamwise and azimuthal velocity distributions as well as a well-defined temperature profile at the jet outlet. The experiments were performed at a Reynolds number of 24000 and a swirl number (ratio between the angular velocity of the pipe wall and the bulk velocity in the pipe) of 0.5.

By means of a specially designed combined X-wire and cold-wire probe it was possible to simultaneously acquire the instantaneous axial and azimuthal velocity components as well as the temperature and compensate the former against temperature variations. The comparison of the swirling and non-swirling cases clearly indicates a modification of the turbulence structure to that effect that the swirling jet spreads and mixes faster than its non-swirling counterpart. It is also shown that the streamwise velocity and temperature fluctuations are highly correlated and that the addition of swirl drastically increases the streamwise passive scalar flux in the near field.

Ort, förlag, år, upplaga, sidor
Stockholm: KTH , 2006. , s. viii, 111
Serie
Trita-MEK, ISSN 0348-467X ; 2006:11
Nyckelord [en]
Fluid mechanics, swirling jet, turbulence, passive scalar, mixing, hot-wire anemometry, cold-wire
Nationell ämneskategori
Strömningsmekanik och akustik
Identifikatorer
URN: urn:nbn:se:kth:diva-4142ISBN: 91-7178-381-4 (tryckt)OAI: oai:DiVA.org:kth-4142DiVA, id: diva2:10907
Presentation
2006-10-26, Seminarierum S40, Teknikringen 8, KTH, 10:30
Opponent
Handledare
Anmärkning
QC 20101124Tillgänglig från: 2006-10-10 Skapad: 2006-10-10 Senast uppdaterad: 2010-11-24Bibliografiskt granskad

Open Access i DiVA

fulltext(3509 kB)729 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 3509 kBChecksumma MD5
15b422b32137159470c89bcda9fd745d32d9b35e666090ef7521ab08e60f973c6a9e156b
Typ fulltextMimetyp application/pdf

Personposter BETA

Örlü, Ramis

Sök vidare i DiVA

Av författaren/redaktören
Örlü, Ramis
Av organisationen
Mekanik
Strömningsmekanik och akustik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 729 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 889 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf