The Unsteady Development of a Turbulent Wake Through a Downstream
Low-Pressure Turbine Blade Passage
Author:
Stieger R. D.1, Hodson H. P.1
Affiliation:
1. Engineering Department, Whittle Laboratory, Cambridge University, Madingley Road, Cambridge, UK
Abstract
Abstract
This paper presents two-dimensional LDA measurements of the convection of a wake through a low-pressure turbine cascade. Previous studies have shown the wake convection to be kinematic, but have not provided details of the turbulent field. The spatial resolution of these measurements has facilitated the calculation of the production of turbulent kinetic energy, and this has revealed a mechanism for turbulence production as the wake convects through the blade row. The measured ensemble-averaged velocity field confirmed the previously reported kinematics of wake convection while the measurements of the turbulence quantities showed the wake fluid to be characterized by elevated levels of turbulent kinetic energy (TKE) and to have an anisotropic structure. Based on the measured mean and turbulence quantities, the production of turbulent kinetic energy was calculated. This highlighted a TKE production mechanism that resulted in increased levels of turbulence over the rear suction surface where boundary-layer transition occurs. The turbulence production mechanism within the blade row was also observed to produce more anisotropic turbulence. Production occurs when the principal stresses within the wake are aligned with the mean strains. This coincides with the maximum distortion of the wake within the blade passage and provides a mechanism for the production of turbulence outside of the boundary layer.
Publisher
ASME International
Subject
Mechanical Engineering
Reference14 articles.
1. Hodson, HP, 1998, “Bladerow Interactions In Low
Pressure Turbines,” Blade Row Interference Effects Axial Turbomachinery
Stages, Von Karman Institute, Brussels, Belgium, in VKI Lecture
Series No. 1998-02, Feb 9. 2. Howell, R. J., Hodson, H. P., Schulte, V., Schiffer,
H-P., Haselbach, F., and Harvey, N. W., 2001, “Boundary Layer Development on the
BR710 and BR715 LP Turbines-The Implementation of High Lift and Ultra High Lift
Concepts,” ASME Paper No. 2001-GT-0441. 3. Cobley, K., Coleman, N., Siden, G., and Arndt, N.,
1997, “Design of New Three Stage Low Pressure Turbine for BMW Rolls-Royce BR715
Engine,” ASME Paper No. 97-GT-419. 4. Meyer, R.
X.
, 1958,
“The Effects of Wakes on the Transient Pressure and Velocity
Distributions in Turbomachines,” ASME J. Basic
Eng., 80, pp.
1544–1552. 5. Hodson, H.
P.
, 1985,
“A Blade-to-Blade Prediction of Wake-Generated Unsteady
Flow,” ASME J. Eng. Gas Turbines Power,
107.
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