Film Cooling Performances at Different Turbulence Intensities Using Conjugate Heat Transfer Analysis

Abstract:

This study presents a numerical investigation of cooling performances of a modified vane of the film-cooled vane reported by Timko (NASA CR-168289) at different mainstream turbulence intensities (Tus). A 3D conjugate heat transfer (CHT) analysis with SST k-ω turbulence model in FLUENT V.15 is used. Three different mechanisms in CHT analysis, i.e. fluid flow, heat convection between solid surfaces and flowing fluid in an external mainstream and internal cooling passages, and heat conduction within the vane structure, are simultaneously considered. Numerical results are conducted in terms of overall cooling effectiveness at Tu=3.3, 10, and 20%. Comparison between overall cooling effectiveness and film effectiveness under adiabatic assumption is discussed at the three Tus, also. The findings of this research indicate the following phenomena: 1) overall cooling effectiveness decreases with Tu, and this effect on the pressure side (PS) is stronger than that on the suction side (SS) in general. 2) By comparison with adiabatic film effectiveness, the level of overall cooling effectiveness in most regions is higher and more uniform than that of adiabatic film effectiveness for all three Tus. 3) In the leading edge (LE), when Tu increases, near the exits of film holes overall cooling effectiveness deteriorates, but adiabatic film effectiveness improves. Furthermore, a large area with relatively low overall cooling effectiveness is able to move with Tu in the LE region.

• Periodical: Applied Mechanics and Materials (Volume 872)
• Pages: 271-278
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.872.271
• Online since: October 2017
• Authors: Prasert Prapamonthon*, Hua Zhao Xu, Jian Hua Wang
• Keywords: Conjugate Heat Transfer, Overall Cooling Effectiveness, Turbulence Intensity

References

[1] R. H. Ni, W. Humber, G. Fan, P. D. Johnson, J. Downs, J. P. Clark, J. P. Koch, Conjugate heat transfer analysis of a film-cooled turbine vane, Proceedings of ASME Turbo Expo 2011: Turbine Technical Conference and Exposition, (2011).

DOI: 10.1115/gt2011-45920

[2] R. H. Ni, W. Humber, G. Fan, J. P. Clark, R. J. Anthony, J. J. Johnson, Comparison of prediction from conjugate heat transfer analysis of a film-cooled turbine vane to experimental data, Proceedings of ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, (2013).

DOI: 10.1115/gt2013-94716

[3] Z. Mazur, A. Herna´ndez-Rossette, R. Garcı´a-Illescas, A. Luna-Ramı´rez, Analysis of conjugate heat transfer of a gas turbine first stage nozzle, Appl. Therm. Eng. 26 (2006) 1796–1806.

DOI: 10.1016/j.applthermaleng.2006.01.025

[4] Q. B. Zhang, H. Z. Xu, J. H. Wang, G. Li, L. Wang, X. Y. Wu, S. Y. Ma, Evaluation of CFD predictions using different turbulence models on a film cooled guide vane under experimental conditions, Proceedings of ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, (2015).

DOI: 10.1115/gt2015-42563

[5] J. Luo, E. H. Razinsky, Conjugate heat transfer analysis of a cooled turbine vane using the V2F turbulence model, ASME J. Turbomach. 129 (2007) 773-781.

DOI: 10.1115/1.2720483

[6] M. Alizadeh, A. Izadi, A. Fathi, Sensitivity analysis on turbine blade temperature distribution using conjugate heat transfer simulation, ASME J. Turbomach. 136 (2014) 011001.

DOI: 10.1115/1.4024637

[7] S. V. Ekkad, H. Du, J. C. Han, Local heat transfer coefficient and film effectiveness distributions on a cylindrical leading edge model using a transient liquid crystal image method, J. Flow Visual. Image Proc. 3 (1996) 129-140.

DOI: 10.1615/jflowvisimageproc.v3.i2-3.20

[8] K. A. Thole, R. W. Radomsky, M. B. Kang, A. Kohli, Elevated freestream turbulence effects on heat transfer for a gas turbine vane, Int. J. Heat Fluid Flow, 23 (2002) 137–147.

DOI: 10.1016/s0142-727x(01)00145-x

[9] L. P. Timko, Energy efficient engine high pressure turbine component test performance report, NASA report, NASA Lewis Res. Center, (1984) NASA CR-168289.

[10] P. Prapamonthon, H. Z. Xu, J. H. Wang, G. Li, Predicting adiabatic film effectiveness of a turbine vane by two-equation turbulence models, Proceedings of ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, (2015).

DOI: 10.1115/gt2015-42565

[11] Z. Q. Ke, Wang, J. H, Numerical investigations of pulsed film cooling on an entire turbine vane, Appl. Therm. Eng. 87 (2015) 117-126.

DOI: 10.1016/j.applthermaleng.2015.05.022

[12] T. I. P. Shih, Y. L. Lin, Controlling secondary-flow structure by leading-edge airfoil fillet and inlet swirl to reduce aerodynamic loss and surface heat transfer, ASME J. Turbomach. 125 (2003) 48-56.

DOI: 10.1115/1.1518503

[13] P. Prapamonthon, H. Z. Xu, W. S. Yang, J. H. Wang, Numerical study of the effects of thermal barrier coating and turbulence intensity on cooling performances of a nozzle guide vane. Energies, 10(3) (2017) 362.

DOI: 10.3390/en10030362