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High resolution PIV measurements around a model turbine blade trailing edge film-cooling breakout

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Abstract

Film cooling downstream of a model turbine blade trailing edge has been studied experimentally. High resolution particle image velocimetry was used to obtain spatially resolved mean velocity and turbulence measurements in the immediate vicinity of the trailing edge breakout. The mean velocity measurements imply the presence of a pair of counter-rotating longitudinal vortices shed from the sides of the breakout lands. The turbulent shear stress measurements above the breakout are significantly intensified as blowing ratio is increased. These results suggest that there is a strong mixing between the film cooling slot jets and the mainstream flow which degrades the film cooling effectiveness.

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Abbreviations

A exit :

Area of the exit slot

c :

Chord length of the NACA0012

d :

Length between the center of the breakout slot and the land

M :

Blowing ratio

\({\mathop Q\limits^\bullet}_{\rm fc}\) :

Film cooling flow rate

R uw :

Reynolds stress correlation coefficient

T aw :

Adiabatic wall temperature

T c :

Coolant temperature

T ∞ :

Mainstream temperature

u,v,w :

Local mean velocities in x, y, z directions, respectively

u ref :

Bulk average velocity

\(\overline{{u^{\prime}u^{\prime}}}\) :

Streamwise Reynolds normal stress component

\(\overline{{u^{\prime}w^{\prime}}}\) :

Reynolds shear stress component

\(\overline{{w^{\prime}w^{\prime}}}\) :

Vertical Reynolds normal stress component

x,y,z :

Fixed Cartesian system

η:

Adiabatic film cooling effectiveness

ρcoolant :

Density of the coolant fluid

ρmainstream :

Density of the mainstream fluid

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Acknowledgments

The present study was funded by the AFOSR under Grant# FA9550-05-1-0183. The authors would like to thank Jongwook Joo for his assistance with the design of the flow geometry. The airfoil model was fabricated by Mr. Frank Medina at the University of Texas El Paso.

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Authors and Affiliations

  1. Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA

    Yude Chen, Claude G. Matalanis & John K. Eaton

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  1. Yude Chen
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  2. Claude G. Matalanis
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  3. John K. Eaton
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Correspondence to Yude Chen.

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Chen, Y., Matalanis, C.G. & Eaton, J.K. High resolution PIV measurements around a model turbine blade trailing edge film-cooling breakout. Exp Fluids 44, 199–209 (2008). https://doi.org/10.1007/s00348-007-0391-2

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  • DOI: https://doi.org/10.1007/s00348-007-0391-2

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