Advertisement

Journal of Mechanical Science and Technology

, Volume 33, Issue 11, pp 5527–5536 | Cite as

Numerical study on unsteady film cooling performance under the mainstream swing condition

  • Wei ZhangEmail author
  • Hui-ren Zhu
  • Quan-peng Yu
  • Guang-chao Li
Article
  • 3 Downloads

Abstract

Significant unsteady film cooling performance of a turbine shroud can be found under the periodic disturbance of rotor blades. The mainstream flow in film cooling on a turbine shroud is simplified as the periodic swing based on the alternate appearance of the cascade passage flow and the blade tip clearance flow. Three-dimensional unsteady numerical simulation was employed to analyze the film cooling effectiveness with a single cylindrical hole injection at mainstream swing frequencies of 100, 160 and 220 Hz, and at blowing ratios of 0.5, 0.8, 1.1 and 1.4, respectively. A steady simulation was also carried out as a comparison. The results show that mainstream swing provides instantaneous film spots. It is a novel phenomenon in film cooling. Spanwise coverage of film was more uniform compared with the steady case. There are considerable differences of film cooling effectiveness under the various mainstream swing frequencies. A larger swing frequency results in higher spanwise averaged time-averaged film cooling effectiveness.

Keywords

Turbine shroud Film cooling effectiveness Blowing ratio Mainstream swing frequency Unsteady numerical simulation 

Nomenclature

D

Diameter of the cylindrical hole, m

U

Mainstream velocity, m/s

T

Temperature, K

t

Time, s

X

Streamwise coordinate, m

Y

Vertical coordinate, m

Z

Spanwise coordinate, m

ρ

Density, kg/m3

μ

Dynamic viscosity, kg/(m×s)

p

Pressure at local location of the cooled surface, Pa

p*

Total pressure at inlet of the mainstream, Pa

f

Swing frequency of the mainstream inlet velocity, Hz

A

Area of a grid, m2

m

The number of time steps in a period

n

The number of spanwise grids

M

Blowing ratio, (ρcUc)/(ρU)

η

Film cooling effectiveness, (T - Taw)/(T- Tc)

ηave

Spanwise averaged film cooling effectiveness, \(\sum\limits_{i = 1}^n {A_i\eta_i} /\sum\limits_{i = 1}^n {A_i}\)

ηta

Time-averaged film cooling effectiveness, \(\sum\limits_{j = 1}^m {\eta_j}/m\)

ηtave

Spanwise averaged time-averaged film cooling effectiveness, \(\sum\limits_{J = 1}^m {\sum\limits_{i = 1}^n {A_{ij}} \eta_{ij}} /\sum\limits_{i = 1}^m {\sum\limits_{i = 1}^n {A_{ij}}} \)

κ

Enhancement factor, (ηtave_f - ηtave_0)/ηtave_0)

θ

Nondimensional excess temperature, (TreTc) / (TTc)

Sr

Strouhal number, Df/U

Re

Reynolds number, ρUD/μ

Φ

Viscous dissipated energy

Cp

Pressure coefficient, (p* - p)/(1 / 2 ρU2)

Subscripts

aw

Adiabatic wall

c

Coolant

Mainstream

ave

Spanwise averaged

tave

Spanwise averaged time-averaged

ta

Time-averaged

tave_f

Spanwise time-averaged of various swing frequencies

tave_0

Spanwise time-averaged without swing frequencies

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Notes

Acknowledgments

This study was supported by the National Natural Science Foundation of China (Grant No. 51406124).

References

  1. [1]
    S. Acharya and Y. Kanani, Advances in film cooling heat transfer, Advances in Heat Transfer (2017).Google Scholar
  2. [2]
    C. Liu, G. Xie, R. Wang and L. Ye, Study on analogy principle of overall cooling effectiveness for composite cooling structures with impingement and effusion, International J. of Heat and Mass Transfer, 127 (2018) 639–650.CrossRefGoogle Scholar
  3. [3]
    J.-H. Kim and K.-Y. Kim, Performance evaluation of a converging-diverging film-cooling hole, International J. of Thermal Sciences, 142 (2019) 295–304.CrossRefGoogle Scholar
  4. [4]
    G. Li, P. Yang, W. Zhang, Z. Wu and Z. Kou, Enhanced film cooling performance of a row of cylindrical holes embedded in the saw tooth slot, International J. of Heat and Mass Transfer, 132 (2019) 1137–1151.CrossRefGoogle Scholar
  5. [5]
    Y. S. Guan, X. Wang, H. Zhang and Y. Li, LBM study on unsteady flow and heat-transfer behaviors of double-row film cooling with various row spacings, International J. of Heat and Mass Transfer, 138 (2019) 1251–1263.CrossRefGoogle Scholar
  6. [6]
    S. Park, H. Chung, S. M. Choi, S. H. Kim and H. H. Cho, Design of sister hole arrangements to reduce kidney vortex for film cooling enhancement, J. of Mechanical Science and Technology, 31(8) (2017) 3981–3992.CrossRefGoogle Scholar
  7. [7]
    S. Rouina, M. Miranda and G. Barigozzi, Experimental investigation of the unsteady flow behavior on a film cooling flat plate, Energy Procedia, 101 (2016) 726–733.CrossRefGoogle Scholar
  8. [8]
    A. K. Sinha, D. G. Bogard and M. E. Crawford, Film-cooling effectiveness downstream of a single row of holes with variable density ratio, J. of Turbomachinery, 113(3) (1991) 442–449.CrossRefGoogle Scholar
  9. [9]
    T. W. Repko, A. C. Nix, S. C. Uysal and A. T. Sisler, Flow visualization of multi-Hole film-cooling flow under varying freestream turbulence levels, J. of Flow Control Measurement & Visualization, 4(1) (2016) 13–29.CrossRefGoogle Scholar
  10. [10]
    L. I. Guangchao, H. Wang, W. Zhang, Z. Kou and R. Xu, Film cooling performance of a row of dual-fanned holes at various injection angles, J. of Thermal Science, 26(5) (2017) 453–458.CrossRefGoogle Scholar
  11. [11]
    W. Colban, K. A. Thole and M. Haendler, A comparison of cylindrical and fan-shaped film-cooling holes on a vane endwall at low and high freestream turbulence levels, J. of Turbomachinery, 130(3) (2008) 528–544.CrossRefGoogle Scholar
  12. [12]
    W.-S. Fu, W.-S. Chao, M. Tsubokura, C.-G. Li and W.-H. Wang, Direct numerical simulation of film cooling with a fan-shaped hole under low Reynolds number conditions, International J. of Heat and Mass Transfer, 123 (2018) 544–560.CrossRefGoogle Scholar
  13. [13]
    J. E. Sargison, M. L. G. Oldfield, S. M. Guo, G. D. Lock and A. J. Rawlinson, Flow visualisation of the external flow from a converging slot-hole film-cooling geometry, Experiments in Fluids, 38(3) (2005) 304–318.CrossRefGoogle Scholar
  14. [14]
    S. Li, Z. Yuan and G. Chen, Numerical investigation of unsteady mixing mechanism in plate film cooling, Theoretical and Applied Mechanics Letters, 6 (2016) 213–221.CrossRefGoogle Scholar
  15. [15]
    S. I. Kim and I. Hassan, Unsteady heat transfer analysis of a film cooling flow, 46 thAiaa Aerospace Sciences Meeting and Exhibit, Reno, Nevada (2008).Google Scholar
  16. [16]
    S. I. Kim and I. Hassan, Unsteady simulations of a film cooling flow from an inclined cylindrical jet, J. of Thermo-physics & Heat Transfer, 24(1) (2010) 145–156.CrossRefGoogle Scholar
  17. [17]
    S. M. Coulthard, R. J. Volino and K. A. Flack, Effect of jet pulsing on film cooling: Part 1 — Effectiveness and flow-field temperature results, J. of Turbomachinery, 129(2) (2007) 232–246.CrossRefGoogle Scholar
  18. [18]
    S. M. Coulthard, R. J. Volino and K. A. Flack, Effect of jet pulsing on film cooling — Part II: Heat transfer results, J. of Turbomachinery, 129(2) (2006) 247–257.CrossRefGoogle Scholar
  19. [19]
    Y. Gao, X. Yan, J. Li and K. He, Investigations into film cooling and unsteady flow characteristics in a blade trailing-edge cutback region, J. of Mechanical Science and Technology, 32(10) (2018) 5015–5029.CrossRefGoogle Scholar
  20. [20]
    J. S. Lee and I. S. Jung, Effect of bulk flow pulsations on film cooling with compound angle holes, International J. of Heat & Mass Transfer, 45(1) (2002) 113–123.CrossRefGoogle Scholar
  21. [21]
    R. J. Fawcett, A. P. S. Wheeler, L. He and R. Taylor, Experimental investigation into unsteady effects on film cooling, J. of Turbomachinery, 134(2) (2011) 021015.Google Scholar
  22. [22]
    T. Yu. Izmodenova, N. N. Kortikov and N. B. Kuznetsov, Unsteady film cooling with imposed nonuniform pulsations of the main flow, Thermophysics & Aeromechanics, 15(4) (2008) 583–588.Google Scholar
  23. [23]
    Y. C. Seo and S. W. Lee, Aerodynamic losses for squealer tip with different winglets, J. of Mechanical Science and Technology, 33(2) (2019) 639–647.CrossRefGoogle Scholar
  24. [24]
    D. Zhang, L. Shi, R. Zhao, W. Shi, Q. Pan and B. P. M. (Bart) van Esch, Study on unsteady tip leakage vortex cavi-tation in an axial-flow pump using an improved filter-based model, J. of Mechanical Science and Technology, 31(2) (2017) 659–667.CrossRefGoogle Scholar
  25. [25]
    C. H. N. Yuen and R. F. Martinez-Botas, Film cooling characteristics of a single round hole at various streamwise angle in a crossflow: Part I. Effectiveness, International J. of Heat and Mass Transfer, 46(2) (2003) 221–235.CrossRefGoogle Scholar
  26. [26]
    B. Amar and D. Rabah, Numerical and experimental investigation of turbine blade film cooling, Heat & Mass Transfer, 53(12) (2017) 3443–3458.CrossRefGoogle Scholar

Copyright information

© KSME & Springer 2019

Authors and Affiliations

  • Wei Zhang
    • 1
    Email author
  • Hui-ren Zhu
    • 1
  • Quan-peng Yu
    • 2
  • Guang-chao Li
    • 2
  1. 1.School of Power and EnergyNorthwestern Polytechnical UniversityXianChina
  2. 2.Department of Aero EngineShenyang Aerospace UniversityShenyangChina

Personalised recommendations