Development of a test rig for investigating the flow field around guide vanes of Francis turbines

Chitrakar, Sailesh; Neopane, Hari Prasad; Dahlhaug, Ole Gunnar

doi:10.1016/j.flowmeasinst.2019.101648

Cited by 10 publications

(3 citation statements)

References 19 publications

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“…In the case of asymmetrical GV profiles like NACA4412, the pressure difference between the two sides of GV was found to be less than that of NACA0012, which helped to reduce the leakage flow and consequences of the vortex filament [12]. In RDA, it can be inferred from Figure 6 that the tip leakage flow along with the resulting vortices can be predicted similar to that of the cascade rig [13]. Furthermore, Figure 7 shows the plot of the velocity component normal to the chord of the GV obtained from RDA and compared to the previous studies conducted on the real turbine.…”

Section: Tip Leakage Vortexmentioning

confidence: 97%

Credibility of Rotating Disc Apparatus for investigating sediment erosion in guide vanes of Francis turbines

Aryal

Chitrakar

Shrestha

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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Estimation of sediment erosion in hydraulic turbines is limited by the broad range of dependent parameters, such as characteristics of sediment, base materials and flow conditions. Some mathematical models have been proposed in the past literatures and some of them has been incorporated in a CFD tool for predicting the erosion together with the flow conditions. Rotating Disc Apparatus is a simplified experimental setup that was initially developed targeting on erosion studies in Francis turbines. However, the closeness of the results obtained from this apparatus with the actual turbine remains uncertain. This paper focuses on investigating the flow phenomena inside the region of guide vanes using RDA and comparing with the actual turbine. A reference case of Jhimruk hydropower plant has been taken in this study, which has been scaled down with a factor of 1.6 from its original size. The numerical fluid domain consists of four rotating blades distributed around the disc uniformly. The pressure distribution around the guide vanes inside RDA along with development of the tip-vortices have been compared with the results from the past research works. The experiment consists of a qualitative analysis of the wear pattern, which has been compared with the results of the CFD. It is found that flow field around guide vanes inside RDA matches closely with that of the real turbine. The stagnation point and development of the pressure and suction sides are similar to the actual guide vanes, which makes the apparatus suitable for investigating the erosion after including the sediment particles. However, more investigations might be needed for using the same apparatus for the runner blades, or guide vanes at different operating conditions.

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Section: Tip Leakage Vortexmentioning

confidence: 97%

Credibility of Rotating Disc Apparatus for investigating sediment erosion in guide vanes of Francis turbines

Aryal

Chitrakar

Shrestha

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

Self Cite

View full text Add to dashboard Cite

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“…Figure 5 also shows the error bar which was constructed with the difference of numerical and experimental value for each GV opening angle. Furthermore, validation of numerical model was also carried out by measuring the pressure around the middle GVs in three-GV cascade rigs developed by Chitrakar et al [34]. The closed loop test setup was equipped with a pump delivering water from a lower reservoir.…”

Section: Validation With Prototype Datamentioning

confidence: 99%

Leakage Vortex Progression through a Guide Vane’s Clearance Gap and the Resulting Pressure Fluctuation in a Francis Turbine

et al. 2021

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A clearance gap (CG) between guide vanes (GVs) and facing plates exists at both ends of a Francis turbine and allows the opening angle to be adjusted for varying operating conditions. Leakage flow is induced through this gap due to the pressure difference between the two sides of the guide vanes. While some research works have used qualitative approaches to visualize and predict the strength of a leakage vortex (LV), this paper presents a method for quantifying vortices along a trajectory. In this paper, a prototype high-head Francis runner with specific speed of 85.4 is considered as a reference case. A systematic investigation across both space and time is carried out, i.e., analysis of the spatial temporal progression of LV for three operating conditions. While travelling from the CG to runner leading edge, LV evolution and trajectory data are observed and the values of vorticity and turbulent kinetic energy are calculated for the LV trajectory. Frequency spectrum analyses of pressure oscillations in the vaneless space, runner blade, and draft tube are also performed to observe the peak pressure pulsation and its harmonics. Unsteady fluctuations of the runner output torque are finally studied to identify the patterns and magnitudes of torque oscillations.

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“…Guide vane sangat berperan penting untuk mengkondisikan pola dan kecepatan aliran angin di dalam ducting [6]- [8]. Pemasangan guide vane mampu meningkatkan efesiensi kerja turbin dan mampu mempengaruhi besarnya kecepatan keluaran angin.…”

Section: Pendahuluanunclassified

Numerical Study: Comparison the Effect of Ratio Length and Diameter Guide Vane of Air Flow on Outlet Ducting

Anggara

2020

SJMEkinematika

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Guide vane sangat berperan dalam pengkondisian pola aliran dan kecepatan fluida sebelum melewati sudu turbin. Dengan konfigurasi pemasangan turbin sumbu aksial sesudah kondensor ac, dibutuhkan guide vane yang mampu menghasilkan kecepatan tinggi pada daerah dekat dinding ducting. Untuk itu penelitian ini dilakukan untuk membandingkan pengaruh rasio dimensi panjang dan diameter menggunakan ANSYS FLUENT 17. Variasi dimensi geometri guide vane dibagi menjadi dua tipe, dimana masing-masing memiliki tiga variasi geometri. Tipe 1dengan rasio dimensi panjang terdiri atas variasi A, B dan C sedangkan tipe 2 dengan rasio dimensi diameter, variasinya adalah D, E dan F. Hasil memperlihatkan bahwa variasi B dan F menghasilkan kecepatan paling tinggi di tipenya. Hal ini karena efek percepatan maksimal pada variasi B dan sudut terkecil guide vane akan mengurangi gaya gesek pada variasi F.

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Development of a test rig for investigating the flow field around guide vanes of Francis turbines

Cited by 10 publications

References 19 publications

Credibility of Rotating Disc Apparatus for investigating sediment erosion in guide vanes of Francis turbines

Credibility of Rotating Disc Apparatus for investigating sediment erosion in guide vanes of Francis turbines

Leakage Vortex Progression through a Guide Vane’s Clearance Gap and the Resulting Pressure Fluctuation in a Francis Turbine

Numerical Study: Comparison the Effect of Ratio Length and Diameter Guide Vane of Air Flow on Outlet Ducting

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