Numerical simulation of transient processes in hydroturbines

Avdyushenko, Alexander; Cherny, S. G.; Чирков, Д. В.; Skorospelov, V. A.; Turuk, P. A.

doi:10.1134/s0869864313050059

Cited by 28 publications

(10 citation statements)

References 3 publications

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“…For example, an elastic model and a nonelastic model based on first-order differential equations for penstock systems have been studied in Refs. [7,14], respectively. However, owning to the complex of nonlinear, time-variant and non-minimum phase of the http://dx.doi.org/10.1016/j.chaos.2015.01.025 0960-0779/Ó 2015 Elsevier Ltd. All rights reserved.…”

Section: Introductionmentioning

confidence: 98%

“…For instance, Liu and Liu [5] studied the stability of a hydropower plant with a linear turbine model in a steady state. Avdyushenko et al [14] made significant contributions to the modeling of the hydro-turbine in the transient state. Meanwhile, there are a lot of published papers about the models of each individual part of the hydro-turbine governing system [15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

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Modeling and stability analysis of a fractional-order Francis hydro-turbine governing system

Chen

Zhang

et al. 2015

Chaos, Solitons & Fractals

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Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Modeling and stability analysis of a fractional-order Francis hydro-turbine governing system

Chen

Zhang

et al. 2015

Chaos, Solitons & Fractals

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“…Liu et al [25,26] simulated the transient power interruption process and load rejection process of a prototype pump-turbine at pump mode by means of a 3-D flow simulation. Avdyushenko et al [27] presented a method that was based on a joint solution to the Reynolds-averaged Navier-Stokes (RANS) equations for incompressible fluid flows to simulate the start-up process in hydro turbines, and comparison with experimental data was also performed. Fu et al [28,29] used a dynamic mesh to solve the load rejection process simulations in a pump-turbine, and the energy transformation and detail transient flow were analyzed.…”

Section: Introductionmentioning

confidence: 99%

Load Rejection Transient Process Simulation of a Kaplan Turbine Model by Co-Adjusting Guide Vanes and Runner Blades

et al. 2018

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To obtain the flow mechanism of the transient characteristics of a Kaplan turbine, a three-dimensional (3-D) unsteady, incompressible flow simulation during load rejection was conducted using a computational fluid dynamics (CFD) method in this paper. The dynamic mesh and re-meshing methods were performed to simulate the closing process of the guide vanes and runner blades. The evolution of inner flow patterns and varying regularities of some parameters, such as the runner rotation speed, unit flow rate, unit torque, axial force, and static pressure of the monitored points were revealed, and the results were consistent with the experimental data. During the load rejection process, the guide vane closing behavior played a decisive role in changing the external characteristics and inner flow configurations. In this paper, the runner blades underwent a linear needle closure law and guide vanes operated according to a stage-closing law of "first fast, then slow," where the inflection point was t = 2.3 s. At the segment point of the guide vane closing curve, a water hammer occurs between guide vanes and a large quantity of vortices emerged in the runner and the draft tube. The pressure at the measurement points changes dramatically and the axial thrust rises sharply, marking a unique time in the transient process. Thus, the quality of a transient process could be effectively improved by properly setting the location of segmented point. This study conducted a dynamic simulation of co-adjustment of the guide vanes and the blades, and the results could be used in fault diagnosis of transient operations at hydropower plants.

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“…Avdyushenko et al. 13 presented some numerical results on start-up, load rejection of a Francis turbine. Zhou et al.…”

Section: Introductionmentioning

confidence: 99%

“…Li et al 12 applied STAR-CCMþ to calculate the shutdown process for a pump-turbine, concluding that with the guide vane closing, both the flow rate and torque declined. Avdyushenko et al 13 presented some numerical results on start-up, load rejection of a Francis turbine. Zhou et al 14 and Liu et al 15 investigated runaway processes of Kaplan turbines, revealing that the pressure fluctuation in draft tube could produce strong vibrations.…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis of transient characteristics of a bulb hydraulic turbine during runaway transient process

Feng

Luo

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part E:

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In this paper, the runaway transient process in a bulb turbine has been investigated by adopting commercial CFD code ANSYS CFX, and transient characteristics in the process have been examined and analyzed in detail. The results show that the predicted maximal runaway rotational speed and flow rate of the turbine are in close agreement with experimental data. During transient process, both the flow rate and rotational speed are rising with time, leading to an increase in both axial and circumferential velocities at the runner outlet. The velocity ratio between them has been diminished greatly at the draft tube inlet, inducing a spiral vortex rope growing with time. The cavitation will shorten the duration and reduce the maximal rotational speed of the runaway process. The runner blade pressure surface is much more critical to cavitation than the suction surface. The amplitude of pressure fluctuation in the runaway process is increasing in the main flow direction. Furthermore, the amplitude of pressure fluctuation reaches up to over 100% of the working head in the draft tube, considerably threatening the safe operation of the turbine.

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Numerical simulation of transient processes in hydroturbines

Cited by 28 publications

References 3 publications

Modeling and stability analysis of a fractional-order Francis hydro-turbine governing system

Modeling and stability analysis of a fractional-order Francis hydro-turbine governing system

Load Rejection Transient Process Simulation of a Kaplan Turbine Model by Co-Adjusting Guide Vanes and Runner Blades

Numerical analysis of transient characteristics of a bulb hydraulic turbine during runaway transient process

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