Publication detail

Reduced order model of draft tube flow

RUDOLF, P. ŠTEFAN, D.

Original Title

Reduced order model of draft tube flow

Type

conference paper

Language

English

Original Abstract

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.

Keywords

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

Authors

RUDOLF, P.; ŠTEFAN, D.

RIV year

2014

Released

1. 12. 2014

Publisher

IOP Science

ISBN

1755-1315

Periodical

IOP Conference Series: Earth and Environmental Science

Year of study

22

Number

1

State

United Kingdom of Great Britain and Northern Ireland

Pages from

1

Pages to

10

Pages count

10

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"
}