Unsteady multi-phase cavitation analysis on the effect of anti-cavity fin installed on a Kaplan turbine runner

Hydraulic turbine runners experience high excitation forces in their daily operations, and these excitations may cause resonances to runners, which may induce high vibrations and shorten the runner's lifetimes. Increasing the added damping of runners in water can be helpful to reduce the vibration level during resonances. Some studies have shown that the modification of the trailing edge shape can be helpful to increase added damping of hydrofoils in water. However, the influence of blade trailing edge shape on the added damping of hydraulic turbine runners has been studied in a limited way before. Due to the difficulties to study this problem experimentally, the influence of blade trailing edge shape on a Kaplan turbine runner has been studied numerically in this paper and the one-way FSI method was implemented. The performances of three different turbulence models, including the k − ϵ , k − ω SST , and transition SST models, in the added damping simulation of the NACA 0009 hydrofoil were evaluated by comparing with the available results of the two-way FSI simulation in the references. Results show that, unlike the significantly different performances in the two-way FSI method, the performances of all the turbulence models are very close in the one-way FSI method. Then, the k − ϵ turbulence model was applied to the added damping simulation of a Kaplan turbine runner, and results show that the modification of the blade trailing edge shape can be helpful to increase the added damping to some extent.

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Repair Welding Methodology for the Glasses of the Kaplan Turbine Runner at the Hydro Power Plant Djerdap 1

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1138.13 ◽

2016 ◽

Vol 1138 ◽

pp. 13-18 ◽

Cited By ~ 2

Author(s):

Miodrag Arsić ◽

Srđan Bošnjak ◽

Vencislav Grabulov ◽

Mladen Mladenović ◽

Zoran Savić

Keyword(s):

Power Plant ◽

Hydro Power ◽

Repair Welding ◽

Generating Sets ◽

Kaplan Turbine ◽

Turbine Runner ◽

Periodic Inspections ◽

Hydroelectric Generating Sets ◽

Non Destructive ◽

Structural Solutions

Vertical Kaplan turbines, manufactured in Russia and with nominal power of 200 MW, have been installed in 6 hydroelectric generating units at hydro power plant Djerdap 1. Hydroelectric generating sets have been designed for the service life of 40 years due to structural solutions and limited possibilities of performing periodic inspections and state analyses.During the rehabilitation of the hydroelectric generating sets, non-destructive tests were performed on all components and structures in order to complete state analysis. In this paper the damages and methodology of repair welding for damaged glasses, which are the integral part of the kinematic system of runner blades, are presented.

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Off-Design Performance Characteristics of Supercavitating Hydrofoils in Cascade

Journal of Basic Engineering ◽

10.1115/1.3425142 ◽

1970 ◽

Vol 92 (4) ◽

pp. 797-806

Author(s):

R. Oba

Keyword(s):

Lift Coefficient ◽

Extreme Case ◽

Flow Speed ◽

Performance Characteristics ◽

Inlet Flow ◽

Design Performance ◽

Kaplan Turbine ◽

The Poor ◽

Turbine Runner

The performance characteristics of supercavitating flapped foils in cascade, (such as the lift coefficient, the drag-lift ratio, and the limiting inlet flow speed) are calculated, for various cascade arrangements and flap angles, as well as flap-chord ratios, e. The extreme case when e = 1.0 corresponds simply to adjusting the cascade angle, such as in the Kaplan-turbine runner. It is found that the poor supercavitating cascade performance characteristics at conditions other than the designed condition, that is, the off-design performance characteristics, are noticeably improved with the use of flapped foils. The characteristics of cascaded foils without flaps, especially where there are no adjustments in cascade angle, make their use impractical in the off-design condition.

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