Tip leakage losses in a linear turbine cascade

An investigation of tip leakage flow and its effects on loss production was performed on a large-scale linear turbine cascade having a tip gap measuring 2.1% of the blade height. The Reynolds number based on axial chord and cascade exit velocity was 4.5x10⁵. The experimental work began with a visualization study of the flow in and around the tip gap. The actual flow measurements consisted of two phases, the tip gap exit plane measurements for determination of the losses incurred within the tip gap, and the downstream measurements for determination of the overall cascade losses. The downstream measurements made 140% of an axial chord downstream of the blade leading edges show the development of the leakage flow and its associated losses. Numerical analyses of the data were used to evaluate various flow properties at both the tip gap exit plane and the downstream measurement plane. Using the measured downstream flow, a mixing analysis was performed to estimate the maximum loss of the cascade. Models of the flow were developed to explain and quantify the various factors contributing to the cascade's overall loss. At a particular downstream location, the additional loss due to tip leakage was found to be the sum of the measured loss at the tip gap exit plane and the amount of tip gap secondary kinetic energy which had been dissipated by that downstream location.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1987

Author dc:creator

• Dishart, Peter T.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

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

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/106172

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/106172