Application of a modified k-[epsilon] turbulence model to gas turbine combustor geometries

The k-epsilon turbulence model yields inconsistent and diffusive results for swirling and recirculating flows, which are characteristic of combustor geometries. Y. S. Chen and S. W. Kim propose a modification to the k-epsilon turbulence model which has shown improved predictions for several complex flows. This study evaluates the application of the Chen modification of the k-epsilon turbulence model to combustor geometries by applying the modification to two burner test cases which contain the elemental flow characteristics of an industrial gas turbine combustor. The modification is implemented into a commercial computational fluid dynamics (CFD) code. The results show an improved prediction of the location, shape and size of the primary centerline recirculation zone for both cases. The large swirl and axial velocity gradients, which are diffused by the standard k-epsilon model, are preserved by the Chen model. The overprediction of turbulent eddy viscosity in regions of high shear, which is characteristic of k-epsilon, is controlled by the Chen modification. In industrial combustor design, the prediction of the location, size and shape of primary flow features is of paramount importance. The Chen modification can, therefore, be considered a successful improvement to the k-epsilon model and can be considered applicable to combustor geometries.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1993

Author dc:creator

• Relation, Heather L.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-10312009-020353

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/45375