Minimizing erosive wear through a CFD multi-objective optimization methodology for different operating points of a Francis turbine

Aponte, Rodríguez; Teran, Leonel A.; Grande, Javier; Coronado, J.J.; Ladino, Alexander; Larrahondo, F.; Rodríguez, S.A.

doi:10.1016/j.renene.2019.07.116

Cited by 45 publications

(16 citation statements)

References 28 publications

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“…As the baffle affected the heat transfer, and the CGP had a guiding effect on the flow, it is expected that the use of both devices could aid future SUT development. This study is a case study based on geometrical parameters; however, in the future, the optimization considering the parameters of the baffle, the CGP, and other geometrical parameters should be performed using the optimization methods such as a design of experiments, artificial neural network, and genetic algorithm [23]. The SUT has been studied in various scales from small scale for laboratory experiments to large scale exceeding a height of 200 m for large power generation.…”

Section: Cooperative Effect Of Cgp and Bafflementioning

confidence: 99%

Additive Aerodynamic and Thermal Effects of a Central Guide Post and Baffle Installed in a Solar Updraft Tower

et al. 2019

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The solar updraft tower (SUT) is a renewable power generation system that uses natural air convection from the ground that is heated by solar radiation. Placing flow-guide structures within the collector of the SUT can enhance aerodynamic performance, and hence, increase the kinetic power. Here, we propose a central guide post (CGP) structure in the SUT that controls updraft flow. The effect of the CGP geometry on aerodynamic performance was investigated using computational fluid dynamics modeling (ANSYS Fluent 19.2) to show that a CGP can play a positive role by preventing stagnation of the airflow at the center of the collector, resulting in increased kinetic power output (up to ~2%). However, excessively long CGPs retarded airflow, resulting in a dramatic decrease in kinetic power output. We also investigated a system with both a CGP (to improve aerodynamic performance and minimize energy loss) and a heat-exchange baffle (to maximize thermal energy transfer). When installed with a proper distance between components, the CGP and baffle showed a combined effect of increasing the kinetic power output by up to 10%. We expect that our proposed method using the CGP and baffle system will contribute to the development of better future SUT technology.

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Section: Cooperative Effect Of Cgp and Bafflementioning

confidence: 99%

Additive Aerodynamic and Thermal Effects of a Central Guide Post and Baffle Installed in a Solar Updraft Tower

et al. 2019

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“…To reduce the loss caused by wear to hydropower plants and pump stations, many scholars have studied wear mechanisms [5,6] and wear-protection technology for hydraulic machinery. Aponte [7] and Jing [8], respectively, adopted the design-optimization method to reduce the damage of sediment to the flow component of a hydro-turbine and pump from the aspect of hydraulic design.…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Solid–Liquid Two-Phase Flow around a NACA0012 Cascade in Sediment-Laden Flow

et al. 2022

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Sediment abrasion may cause the removal of material and efficiency loss to hydraulic machinery (hydro-turbine, pump, etc.), which may worsen the internal flow and endanger the safe operation of the machines. As abrasion is caused by the impact of sediment on the solid surface, the movement of particles determines the wear intensity. To understand the wear mechanism of hydraulic machinery, the motion characteristics of the asymmetric solid–liquid two-phase flow in a sediment-laden flow around NACA0012 cascades were studied. The laser particle imaging velocimetry (PIV) method was used to measure the flow of quartz particles with median diameters d50 of 82.7 μm, 65.9 μm, and 31.8 μm near the wall of cascades at an impact angle of 10° in a Venturi circuit. The flow characteristics and velocity slip between solid and liquid phases, as well as the effects of particle size and the Reynolds number on velocity slip, were analyzed. The results showed that: (1) the flow is asymmetrically distributed in front of the cascade’s leading edge at a 10° impact angle, and there is strong velocity slip between solid and liquid phases; (2) under the influence of particle inertia, the velocity of the solid phase is higher than that of the liquid phase in the deceleration stage, while the velocity of the solid phase is lower than that of liquid phase in the acceleration stage; (3) in the process of approaching the leading edge, the velocity difference between the solid and liquid phase increases by about 10% and the angle difference increases by about 8.8°.

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“…The sediment erosion occurs at various parts in the hydro turbine, Vanes and buckets of Francis and Pelton runners are important part which determine the efficiency of the turbine directly. Many works using numerical simulation and experiments have been reported [1][2][3][4][5][6][7][8]. The runner seal of the Francis turbine is also important part.…”

Section: Introductionmentioning

confidence: 99%

A study of sediment erosion of runner seal of a Francis turbine

Yonezawa

Watamura

2022

J. Phys.: Conf. Ser.

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Suspended sediment particles included in working fluid of hydro turbines often cause erosion and reduce reliability and lifetime of the hydro turbine. It is important for understanding and suppressing erosion problems to understand characteristics of two-phase-flows of liquid and solid particles. In the present study, experimental and numerical studies were carried out to understand mechanisms of erosion in runner seal of a Francis turbine. The experiments were carried out using small-scale seal models. Flow patterns were visualized using coated mica flakes to understand entire flow patterns and a particle image velocimetry were also carried out to measure velocity field in a meridional cross-section. Accelerated erosion tests were also carried out and it was observed similar erosion distributions to that was observed in the actual hydro-turbine. Numerical flow simulations were also carried out to examine mechanisms of the erosion, contributions of each forces acting on the particles and appropriate parameters to capture characteristics of liquid-solid flows and erosion distribution, which were observed in experiments.

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Minimizing erosive wear through a CFD multi-objective optimization methodology for different operating points of a Francis turbine

Cited by 45 publications

References 28 publications

Additive Aerodynamic and Thermal Effects of a Central Guide Post and Baffle Installed in a Solar Updraft Tower

Additive Aerodynamic and Thermal Effects of a Central Guide Post and Baffle Installed in a Solar Updraft Tower

Asymmetric Solid–Liquid Two-Phase Flow around a NACA0012 Cascade in Sediment-Laden Flow

A study of sediment erosion of runner seal of a Francis turbine

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