Fluid flow analysis of drooping phenomena in pump mode for a given guide vane setting of a pump-turbine model

Li, Deyou; Gong, Ruzhi; Wang, Hongjie; Fu, W. W.; Wei, Xianzhu; Liu, Zhansheng

doi:10.1631/jzus.a1500087

Cited by 18 publications

(9 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The distribution of flow angles is also numerically presented at the leading and trailing edge from the crown to the band. 10 Pavesi et al. 11 showed qualitative agreement between the head curves in simulation and experiment.…”

Section: Introductionmentioning

confidence: 85%

See 1 more Smart Citation

Suppression of hump characteristic for a pump-turbine using leading-edge protuberance

Guo

Chihang

Zhou

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

The application of wave guide vanes with bio-inspired leading-edge protuberances to the hump characteristic of a pump-turbine is examined in this study. Numerical simulation with a shear-stress transport turbulence model is used to calculate the three-dimensional flow in a pump-turbine in pumping mode. Three tubercle amplitudes of 0.02c, 0.04c, and 0.08c (c is chord length), and three spanwise wavenumbers (2/s, 4/s and 8/s, s is the length of span) for guide vanes are especially considered. The results obtained show that the simulated performances of original guide vanes are found to be in good qualitative agreement with experimental data, supporting the validation of the computational fluid dynamics method. For different wave guide vanes with leading-edge protuberances, it is shown that the hump characteristic of the pump-turbine in pumping mode is effectively improved. This is due to improved flow fields below the tongue in view of entropy production and vector field. The energy loss can be clearly compared through the entropy distribution for different locations of the guide vanes, and it is improved for the wave guide vanes with bio-inspired leading-edge protuberances. For current pump-turbine, the optimal amplitude and wavenumber are found to be around 0.04c and 4/s.

show abstract

Section: Introductionmentioning

confidence: 85%

“…The SST k-ω model 14,15 effectively blends the robust and accurate k-ω model in the near-wall region with the free-stream independence of the k –ɛ model in the far field, which has been adopted in previous relative research on pump-turbine. 8–10 The principle formulation of SST k-ω model is given by …”

Section: Numerical Methodologymentioning

confidence: 99%

Suppression of hump characteristic for a pump-turbine using leading-edge protuberance

Guo

Chihang

Zhou

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part A:

View full text Add to dashboard Cite

show abstract

“…To acquire α , we utilise the curve of the closing law of the guide vane in the load rejection transient, as shows in Fig. 2 [4, 12, 13, 25–29].…”

Section: Non‐linear Dynamic Mathematical Model Of the Hegsmentioning

confidence: 99%

Dynamic analysis and modelling of a Francis hydro‐energy generation system in the load rejection transient

Chen

Zhang

et al. 2016

IET Renewable Power Generation

View full text Add to dashboard Cite

In this study, the authors propose a novel non‐linear mathematical model of a hydro‐energy generation system in the load rejection transient considering the elastic water hammer‐impact of the penstock and the non‐linear characteristics of the generator. More specifically, six dynamic transfer coefficients of the hydro‐turbine are introduced to the generation system. Furthermore, the dynamic behaviours of the system are investigated using bifurcation diagrams and time waveforms from the point of engineering. Finally, these methods and analytical results will supply some principles for designing and running a hydropower station.

show abstract

“…(∆c u¨u ) can be determined by Equations (4) and (5). For the experimental method, Equation (4) gives an approximate value of Euler torque [16]. Energy coefficients for hydraulic losses and gross energy obtained from the rotating runner could be calculated through the Equations (6) and (7).…”

Section: Analysis Of Energy Dropmentioning

confidence: 99%

Hysteresis Characteristic in the Hump Region of a Pump-Turbine Model

Wang

Chen

et al. 2016

Energies

Self Cite

View full text Add to dashboard Cite

Abstract:The hump feature is one of the major instabilities in pump-turbines. When pump-turbines operate in the hump region, strong noise and serious fluctuations can be observed, which are harmful to their safe and stable operation and can even destroy the whole unit as well as water conveyance system. In this paper, a low specific speed (n q = 36.1 min´1) pump-turbine model was experimentally investigated. Firstly, the hump characteristic was obtained under 19 mm guide vane opening conditions. More interestingly, when the hump characteristic was measured in two directions (increasing and decreasing the discharge), characteristic hysteresis was found in the hump region. The analysis of performance characteristics reveals that the hump instability is the result of Euler momentum and hydraulic losses, and different Euler momentum and hydraulic losses in the two development processes lead to the hysteresis phenomenon. Then, 12 pressure sensors were mounted in the different parts of the pump-turbine model to obtain the time and frequency characteristics. The analysis of the corresponding fast Fourier transform confirms that the hump characteristic is related to low-frequency (0.04-0.15 times rotational frequency) vortices. The occurrence and cessation of vortices depend on the operating condition and measurement direction, which contribute to the hysteresis feature. Finally, the type of the low-frequency vortices was analyzed through the cross power spectrum.

show abstract

Fluid flow analysis of drooping phenomena in pump mode for a given guide vane setting of a pump-turbine model

Cited by 18 publications

References 18 publications

Suppression of hump characteristic for a pump-turbine using leading-edge protuberance

Suppression of hump characteristic for a pump-turbine using leading-edge protuberance

Dynamic analysis and modelling of a Francis hydro‐energy generation system in the load rejection transient

Hysteresis Characteristic in the Hump Region of a Pump-Turbine Model

Contact Info

Product

Resources

About