Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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
Informal introduction to program structure of spectral interpolation in nek5000
KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control.
KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control.ORCID iD: 0000-0002-7448-3290
KTH, School of Engineering Sciences (SCI), Mechanics, Stability, Transition and Control.ORCID iD: 0000-0001-9627-5903
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The algorithm of the interpolation implementation in the spectral element codenek5000is documented informally. The original code is written by James Lottes at Argonne National Laboratories. The various steps of the operations are generally described and visualised for a typical deformed mesh. The corresponding routines and their argument lists for each stage of the interpolation are also explained. The memory structure of the implementation is briefly discussed. Finally, the code overview of the routines is presented.

National Category
Mechanical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-177308OAI: oai:DiVA.org:kth-177308DiVA: diva2:872182
Note

QS 2015

Available from: 2015-11-18 Created: 2015-11-18 Last updated: 2015-11-18Bibliographically approved
In thesis
1. Particle-laden Turbulent Wall-bounded Flows in Moderately Complex Geometries
Open this publication in new window or tab >>Particle-laden Turbulent Wall-bounded Flows in Moderately Complex Geometries
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Wall-bounded turbulent dispersed multiphase flows occur in a variety of industrial, biological and environmental applications. The complex nature of the carrier and the particulate phase is elevated to a higher level when introducing geometrical complexities such as curved walls. Realising such flows and dispersed phases poses challenging problems both from computational and also physical point of view. The present thesis addresses some of these issues by studying a coupled Eulerian–Lagrangian computational framework.

The content of the thesis addresses both turbulent wall flows and coupled particle motion. In the first part, turbulent flow in straight pipes is simulated by means of direct numerical simulation (DNS) with the spectrally accurate code nek5000  to examine the Reynolds-number effect on turbulence statistics. The effect of the curvature to these canonical turbulent pipe flows is then added to generate Prandtl’s secondary motion of first kind. These configurations, as primary complex geometries in this study, are examined by means of statistical analysis to unfold the evolution of turbulence characteristics from a straight pipe. A fundamentally different Prandtl’s secondary motion of the second kind is also put to test by adding side-walls to a canonical turbulent channel flow and analysing the evolution of various statistical quantities with varying the duct width-to-height aspect ratios.

Having obtained a characterisation of the turbulent flow in the geometries of bent pipes and ducts, the dispersion of small heavy particles is modelled in these configurations by means of point particles which are one-way coupled to the flow. For this purpose a parallel Lagrangian Particle Tracking (LPT) scheme is implemented in the spectral-element code nek5000 . Its numerical accuracy, parallel scalability and general performance in realistic situations is scrutinised. The analysis of the resulting particle fields shows that even a small amount of secondary motion has a profound impact on the particle phase dynamics and its concentration maps.

For each of the aforementioned turbulent flow cases new and challenging questions have arisen to be addressed in the present research works. The goal of extending understanding of the particle dispersion in turbulent bent pipes and rectangular ducts are also achieved.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. xii, 71 p.
Series
TRITA-MEK, ISSN 0348-467X ; 2015:09
Keyword
turbulent, complex geometry, particle
National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Mechanics
Identifiers
urn:nbn:se:kth:diva-177310 (URN)978-91-7595-785-2 (ISBN)
Public defence
2015-12-04, F3, Lindstedtsvägen 26, KTH, Stockholm, 11:01 (English)
Opponent
Supervisors
Funder
Swedish e‐Science Research Center
Note

QC 20151118

Available from: 2015-11-18 Created: 2015-11-18 Last updated: 2015-11-18Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Peplinski, AdamSchlatter, Philipp

Search in DiVA

By author/editor
Noorani, AzadPeplinski, AdamSchlatter, Philipp
By organisation
Stability, Transition and Control
Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 259 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • 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