Investigation of two-equation turbulence models applied to a confined axis-symmetric swirling flow

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding

Abstract

The modeling of industrial combustion applications today is almost exclusively based on two-equation turbulence models. Despite its known limitations, the most the widely used model is still the standard k-ε model. The objective of this paper is to investigate the performance of two-equation turbulence models applied to a confined swirling flow. Numerical modeling of an axis-symmetric confined sudden expansion, followed by a contraction with the assumption of steady flow and an incompressible fluid, has been conducted. The flow field is what can be expected in simplified dump gas turbine combustor geometry. In this investigation, three different swirl cases were considered: no swirl, moderate swirl (no central re-circulation zone) and strong swift (a central recirculation zone occurring). The models investigated were: the standard k-ε model, a curvature-modified k-ε model, Chen's k-ε model, a cubic non-linear k-ε model, the standard k-ω model and the Shear Stress Transport (SST) k-ω model. The results show that almost all models were able to predict the major impact of the moderate swirl: reduced outer re-circulation lengths and retardation of the axial velocity on the center-line. However, the Chen k-ε model and the SST k-ω model were found to better reproduce the mean velocity field and the turbulent kinetic energy field from the measurements. For a strong swift, a large re-circulation zone is formed along the center-line, which the standard k-ε model and the modified k-ε model fail to predict. However, the shape and size of the re-circulation zone differ strongly between the models. At this swirl number, the performances of all models were, without exception, worse than for the lower swift numbers. The SST k-ω model achieved the best agreement between computations and experimental data.

Details

Authors
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering

Keywords

  • Gas turbine combustors
Original languageEnglish
Title of host publicationAmerican Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP
PublisherAmerican Society Of Mechanical Engineers (ASME)
Pages199-206
Volume448
Publication statusPublished - 2002
Publication categoryResearch
Peer-reviewedYes
EventComputational technologies for Fluid/Thermal/Structural/Chemical Systems with Industrial Applications (2002 ASME Prssure Vessels and Piping Conference) - Vancouver, BC, Canada
Duration: 2002 Aug 52002 Aug 9

Publication series

Name
Number2
Volume448
ISSN (Print)0277-027X

Conference

ConferenceComputational technologies for Fluid/Thermal/Structural/Chemical Systems with Industrial Applications (2002 ASME Prssure Vessels and Piping Conference)
CountryCanada
CityVancouver, BC
Period2002/08/052002/08/09