Numerical analysis and performance enhancement of a cross-flow hydro turbine

Acharya, Nirmal; Kim, Chang-Gu; Thapa, Bhola; Lee, Young‐Ho

doi:10.1016/j.renene.2015.01.064

Cited by 65 publications

(25 citation statements)

References 3 publications

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“…Because the studies under review modeled the whole turbine, it seems better to review them chronologically, rather than by specific feature, as was done in the previous Section. Recent RANS simulations include [4,6,[23][24][25][26]; however, they provide little of the flow, and do not address the design problem of improving efficiency. These studies have employed the k-and shear stress transport (SST) k-ω turbulence models with homogeneous, two-phase free-surface models for water and air.…”

Section: Computational Studiesmentioning

confidence: 99%

“…Because the studies under review modeled the whole turbine it seems better to review 183 them chronologically, rather than by specific feature, as was done in the previous Section. Recent 184 RANS simulations include [6], [23], [24], [25], [26], and [4], however, they provide few of the flow , and The key nozzle design principle: the need for conversion of head into kinetic energy at the runner entry, formulated by [2], was not considered previously, and little information is available in prior studies on the role of the entry velocities u θ and u r , or β 1 on the runner performance and turbine efficiency.…”

Section: Computational Studiesmentioning

confidence: 99%

“…The improvement, however, is relative to η max ≈ 80%. Apart from Acharya et al [25], discussed below, this is the only computational study to include a guide vane, but, unfortunately, no details were provided of the nozzle flow and the effect of the guide vane on it. They also showed that an air-layer in the blade passages, via suction through air vents around the runner, improved efficiency by reducing recirculation in the blade passages.…”

Section: Computational Studiesmentioning

confidence: 99%

“…Acharya et al [25] performed steady RANS computations on a turbine with η max = 63%. They used the SST k-ω turbulence model with the homogeneous multiphase model for modeling water and air with free-surface effects.…”

Section: Computational Studiesmentioning

confidence: 99%

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The Design of High Efficiency Crossflow Hydro Turbines: A Review and Extension

Adhikari

Wood

2018

Energies

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Efficiency is a critical consideration in the design of hydro turbines. The crossflow turbine is the cheapest and easiest hydro turbine to manufacture and so is commonly used in remote power systems for developing countries. A longstanding problem for practical crossflow turbines is their lower maximum efficiency compared to their more advanced counterparts, such as Pelton and Francis turbines. This paper reviews the experimental and computational studies relevant to the design of high efficiency crossflow turbines. We concentrate on the studies that have contributed to designs with efficiencies in the range of 88-90%. Many recent studies have been conducted on turbines of low maximum efficiency, which we believe is due to misunderstanding of design principles for achieving high efficiencies. We synthesize the key results of experimental and computational fluid dynamics studies to highlight the key fundamental design principles for achieving efficiencies of about 90%, as well as future research and development areas to further improve the maximum efficiency. The main finding of this review is that the total conversion of head into kinetic energy in the nozzle and the matching of nozzle and runner designs are the two main design requirements for the design of high efficiency turbines.

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Section: Computational Studiesmentioning

confidence: 99%

Section: Computational Studiesmentioning

confidence: 99%

Section: Computational Studiesmentioning

confidence: 99%

Section: Computational Studiesmentioning

confidence: 99%

See 2 more Smart Citations

The Design of High Efficiency Crossflow Hydro Turbines: A Review and Extension

Adhikari

Wood

2018

Energies

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show abstract

“…Acharya et el. [7] conducted numerical research involving the modification of nozzle radius, varying the guide vane angle, and changing the number of runner blades. From this study, it has been observed that the highest efficiency of 76.6 % was obtained with 22 blades.…”

Section: Introductionmentioning

confidence: 99%