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Research Papers: Flows in Complex Systems

Experimental Analysis of Cavitation Phenomena on Kaplan Turbine Blades Using Flow Visualization

[+] Author and Article Information
Andrej Podnar

Faculty of Mechanical Engineering,
University of Ljubljana,
Aškerčeva 6,
Ljubljana 1000, Slovenia
e-mail: andrej.podnar@gmail.com

Matevž Dular

Faculty of Mechanical Engineering,
University of Ljubljana,
Aškerčeva 6,
Ljubljana 1000, Slovenia
e-mail: matevz.dular@fs.uni-lj.si

Brane Širok

Faculty of Mechanical Engineering,
University of Ljubljana,
Aškerčeva 6,
Ljubljana 1000, Slovenia
e-mail: brane.sirok@fs.uni-lj.si

Marko Hočevar

Faculty of Mechanical Engineering,
University of Ljubljana,
Aškerčeva 6,
Ljubljana 1000, Slovenia
e-mail: marko.hocevar@fs.uni-lj.si

1Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received October 11, 2017; final manuscript received October 23, 2018; published online January 7, 2019. Assoc. Editor: Satoshi Watanabe.

J. Fluids Eng 141(7), 071101 (Jan 07, 2019) (13 pages) Paper No: FE-17-1656; doi: 10.1115/1.4041985 History: Received October 11, 2017; Revised October 23, 2018

In this study, a comparison of two different Kaplan turbine runners with differently shaped turbine blades was performed. The two turbines differed in the selection of the hydrofoil, the main hydrofoil parameters of which had been modified including, the position of maximum thickness and curvature and the inlet edge radius. Both turbines (unmodified and modified hydrofoils) were tested on a rig designed for low pressure model turbine acceptance tests. The effect of blade shape on cavitation inception, development, and intensity was demonstrated using computer aided visualization. Visualization was performed on the suction side of Kaplan runner blade where the shape of the blade determines cavitation inception and development. The modified Kaplan turbine reduced the cavitation phenomena, and as a result, both turbine performance and output increased for the selected operating points. This demonstrates that choosing the right turbine blade shape is key for optimal turbine performance.

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References

Brandi, R. B. S. , Ramos, T. P. , David, P. A. M. S. , Dias, B. H. , da Silva Junior, I. C. , and Marcato, A. L. M. , 2016, “ Maximizing Hydro Share in Peak Demand of Power Systems Long-Term Operation Planning,” Electr. Power Syst. Res., 41, pp. 264–271. [CrossRef]
Egre, D. , and Milewski, J. C. , 2002, “ The Diversity of Hydropower Projects,” Energy Policy, 30(14), pp. 1225–1230. [CrossRef]
Bajcar, T. , Širok, B. , and Eberlinc, M. , 2009, “ Quantification of Flow Kinematics Using Computer-Aided Visualization,” Strojniški vestnik—J. Mech. Eng., 55(4), pp. 215–223. https://www.sv-jme.eu/?ns_articles_pdf=/ns_articles/files/ojs3/1567/submission/1567-1-1907-1-2-20171103.pdf&id=4935
Rus, T. , Dular, M. , Širok, B. , Hočevar, M. , and Kern, I. , 2007, “ An Investigation of the Relationship Between Acoustic Emission, Vibration, Noise and Cavitation Structures on a Kaplan Turbine,” ASME J. Fluids Eng., 129(9), pp. 1112–1122. [CrossRef]
Cenčič, T. , Hočevar, M. , and Širok, B. , 2014, “ Study of Erosive Cavitation Detection in Pump Mode of Pump-Storage Hydropower Plant Prototype,” ASME J. Fluids Eng., 136(5), p. 051301. [CrossRef]
Širok, B. , Dular, M. , and Stoffel, B. , 2006, Kavitacija, Vol. 1, Fakulteta za strojništvo, Slovenia.
Eichler, O. , and Jaeger, E. U. , 1979, “ The Assessment of the Cavitation Behavior of Kaplan Turbines on the Basis of a Comparison Between Model Tests and Field Experience,” Voith Res. Constr., 25(e), p. 4.
De Lucia, M. , and Anguzza, G. , 1994, “ Visualization and Image Processing to Study the Cavitation Process in Hydraulic Turbomachinery,” Modelling, Testing and Monitoring for Hydro Powerplants Conference Papers, Budapest, Hungary, July 11–13, pp. 383–389.
Stefanović, Z. , 2005, Aeroprofili, Mašinski fakultet, Beograd, Serbia.
Riegels, W. , 1958, Aerodynamische Profile, Oldenbourg, München, Germany.
Kuethe, A. M. , and Schetzer, J. D. , 1959, Foundations of Aerodynamics, 2nd ed., Department of Aeronautical Engineering, Wiley, New York.
Avellan, F. , 2004, “ Introduction to Cavitation in Hydraulic Machinery,” Sixth International Conference on Hydraulic Machinery and Hydrodynamics, Timisoara, Romania, Oct. 21–22, pp. 11–22.
IEC, 1999, “Hydraulic Turbines, Storage Pumps and Pump-Turbines—Model Acceptance Tests,” 2nd ed., International Electrotechnical Commission, International Electrotechnical Commission, Geneva, Switzerland,, Standard No. IEC 60193:1999.
Kercan, V., Djelić, V., Vujanič, V., Rus, T., and Peršin Z., 2010, “ Measurement Methods and Equipment on Turbine Test Rigs,” Turboinštitut, Ljubljana, Slovenia, Report No. 2646e.
Kercan, V., Djelić, V., Vujanič, V., Rus, T., and Peršin Z., 2010, “ Low Pressure Turbine Test Rig,” Turboinštitut, Ljubljana, Slovenia, Report No. 2299e.
Chanson, H. , 2013, “ Advective Diffusion of Air Bubbles in Turbulent Water Flows,” Fluid Mechanics of Environmental Interfaces, 2nd ed., C. Gualtieri , and D. T. Mihailovic , eds., Taylor and Francis, Leiden, The Netherlands, pp. 181–219.
Širok, B. , Potočar, E. , and Novak, M. , 2000, “ Analiza Kinematike Toka za Utripajočim Profilom Spremenljive Geometrijske Oblike z Uporabo Računalniške Vizualizacije,” Strojniški Vestnik, 46, pp. 330–341. https://www.sv-jme.eu/?ns_articles_pdf=/ns_articles/files/ojs3/851/submission/851-1-2346-1-2-20171103.pdf&id=4249
Brennen, C. E. , 1994, Cavitation and Bubble Dynamics, Oxford University Press, New York.

Figures

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Fig. 2

Most important parameters that set characteristics of turbine blade profiles

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Fig. 1

Location of extracted turbine blade profile on Kaplan runner blade, left: unmodified shape and right: modified shape

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Fig. 3

The difference in shape of both turbine blade profiles

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Fig. 4

Experimental setup

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Fig. 5

Original Kaplan turbine hill diagram with six selected ψ at blade angle β = 25 deg (courtesy of the Turboinstitute)

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Fig. 6

Runner blade angle β selection

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Fig. 7

Cavitation curves for both runners at an ψ1 = 0.3346

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Fig. 8

Cavitation curves for both runners at an ψ2 = 0.2857

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Fig. 9

Cavitation curves for both runners at an ψ3 = 0.2521

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Fig. 10

Cavitation curves for both runners at an ψ4 = 0.1513

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Fig. 11

Cavitation curves for both runners at an ψ5 = 0.2062

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Fig. 12

Cavitation curves for both runners at an ψ6 = 0.4034

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Fig. 13

Standard deviation S and time-averaged grayscale intensity Ak,t of cavitation structures for modified runner (left at σ = 0.9) and unmodified runner (right at σ = 1.2) at operating point (ψ1 = 0.3346 and φ = 0.308)

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Fig. 16

Standard deviation S and time-averaged grayscale intensity Ak,t of cavitation structures for modified runner (left at σ = 2.0) and unmodified runner (right at σ = 2.4) at operating point (ψ4 = 0.1513 and φ = 0.30)

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Fig. 17

Standard deviation S and time-averaged grayscale intensity Ak,t of cavitation structures for modified runner (left at σ = 1.6) and unmodified runner (right at σ = 1.9) at operating point (ψ5 = 0.206 and φ = 0.305)

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Fig. 14

Standard deviation S and time-averaged grayscale intensity Ak,t of cavitation structures for modified runner (left at σ = 1.2) and unmodified runner (right at σ = 1.5) at operating point (ψ2 = 0.2857 and φ = 0.31)

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Fig. 15

Standard deviation S and time-averaged grayscale intensity Ak,t of cavitation structures for modified runner (left at σ = 1.3) and unmodified runner (right at σ = 1.6) at operating point (ψ3 = 0.252 and φ = 0.318)

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Fig. 18

Standard deviation S and time-averaged grayscale intensity Ak,t of cavitation structures for modified runner (left at σ = 0.7) and unmodified runner (right at σ = 1.0) at operating point (ψ6 = 0.4034 and φ = 0.313)

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