Detail publikačního výsledku

Reduced order model of draft tube flow

RUDOLF, P.; ŠTEFAN, D.

Originální název

Reduced order model of draft tube flow

Anglický název

Reduced order model of draft tube flow

Druh

Stať ve sborníku v databázi WoS či Scopus

Originální abstrakt

Swirling flow with compact coherent structures is very good candidate for proper orthogonal decomposition (POD), i.e. for decomposition into eigenmodes, which are the cornerstones of the flow field. Present paper focuses on POD of steady flows, which correspond to different operating points of Francis turbine draft tube flow. Set of eigenmodes is built using a limited number of snapshots from computational simulations. Resulting reduced order model (ROM) describes whole operating range of the draft tube. ROM enables to interpolate in between the operating points exploiting the knowledge about significance of particular eigenmodes and thus reconstruct the velocity field in any operating point within the given range. Practical example, which employs axisymmetric simulations of the draft tube flow, illustrates accuracy of ROM in regions without vortex breakdown together with need for higher resolution of the snapshot database close to location of sudden flow changes (e.g. vortex breakdown). ROM based on POD interpolation is very suitable tool for insight into flow physics of the draft tube flows (especially energy transfers in between different operating points), for supply of data for subsequent stability analysis or as an initialization database for advanced flow simulations.

Anglický abstrakt

Swirling flow with compact coherent structures is very good candidate for proper orthogonal decomposition (POD), i.e. for decomposition into eigenmodes, which are the cornerstones of the flow field. Present paper focuses on POD of steady flows, which correspond to different operating points of Francis turbine draft tube flow. Set of eigenmodes is built using a limited number of snapshots from computational simulations. Resulting reduced order model (ROM) describes whole operating range of the draft tube. ROM enables to interpolate in between the operating points exploiting the knowledge about significance of particular eigenmodes and thus reconstruct the velocity field in any operating point within the given range. Practical example, which employs axisymmetric simulations of the draft tube flow, illustrates accuracy of ROM in regions without vortex breakdown together with need for higher resolution of the snapshot database close to location of sudden flow changes (e.g. vortex breakdown). ROM based on POD interpolation is very suitable tool for insight into flow physics of the draft tube flows (especially energy transfers in between different operating points), for supply of data for subsequent stability analysis or as an initialization database for advanced flow simulations.

Klíčová slova

draft tube, proper orthogonal decomposition, POD, reduced order model, vortex rope

Klíčová slova v angličtině

draft tube, proper orthogonal decomposition, POD, reduced order model, vortex rope

Autoři

RUDOLF, P.; ŠTEFAN, D.

Rok RIV

2016

Vydáno

01.12.2014

Nakladatel

IOP Science

Kniha

IOP Conference Series-Earth and Environmental Science

ISSN

1755-1315

Periodikum

IOP Conference Series: Earth and Environmental Science

Svazek

22

Číslo

1

Stát

Spojené království Velké Británie a Severního Irska

Strany od

1

Strany do

10

Strany počet

10

Plný text v Digitální knihovně

http://hdl.handle.net/

BibTex

@inproceedings{BUT111326,
  author="Pavel {Rudolf} and David {Štefan}",
  title="Reduced order model of draft tube flow",
  booktitle="IOP Conference Series-Earth and Environmental Science",
  year="2014",
  journal="IOP Conference Series: Earth and Environmental Science",
  volume="22",
  number="1",
  pages="1--10",
  publisher="IOP Science",
  doi="10.1088/1755-1315/22/2/022022",
  issn="1755-1315"
}