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The impact of combustor turbulence on turbine loss mechanisms

Accepted version
Peer-reviewed

Type

Conference Object

Change log

Authors

Folk, M 
Miller, RJ 
Coull, JD 

Abstract

jats:titleAbstract</jats:title> jats:pA blade row which is located downstream of a combustor has an extremely high turbulence intensity at inlet, typically above 10%. The peak turbulent length scale is also high, at around 20% of the chord of the downstream blade row. In a combustor, the turbulence is created by impinging jets in cross flow. This may result in the turbulence being anisotropic in nature. The aim of this paper is to investigate the effect of combustor turbulence on the loss mechanisms which occur in a turbine blade row. The paper has a number of important findings. The combustor turbulence is characterized and is shown to be isotropic in nature. It shows that, when no pressure gradient is present, combustor turbulence increases the loss of a turbulent boundary layer by 22%. The mechanism responsible for this change is shown to be a deep penetration of the turbulence into the boundary layer. It shows that the presence of combustor turbulence increases the profile loss and endwall loss in the turbine cascade studied by 37% and 47%, respectively. The presence of combustor turbulence also introduces a freestream loss resulting in the total loss of the turbine cascade rising by 47%. When these loss mechanisms were applied to the vane alone, of an engine representative high pressure turbine, it was found to result in a 1.3% reduction in stage efficiency.</jats:p>

Description

Keywords

4012 Fluid Mechanics and Thermal Engineering, 40 Engineering, 4001 Aerospace Engineering

Journal Title

Proceedings of the ASME Turbo Expo

Conference Name

ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition

Journal ISSN

Volume Title

2B-2019

Publisher

American Society of Mechanical Engineers
Sponsorship
EPSRC (1543239)
Rolls-Royce and EPSRC Cenre for Doctoral Training in Gas Turbine Aerodynamics