Numerical analysis of a shrouded micro-hydrokinetic turbine unit

Riglin, Jacob; Schleicher, W. Chris; Öztekin, Alparslan

doi:10.1080/00221686.2015.1032375

Cited by 16 publications

(10 citation statements)

References 13 publications

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“…This indicates that turbine design with diffuser is even more favorable at relatively low velocities, where viscous and dissipative effects are significant. Performed numerical investigations of diffuser-augmented hydrokinetic turbine, presented in [33], indicate the necessity of diffuser shape optimization. According to [34] optimization strategies are used in turbomachinery design to accomplish several requirements that assume more efficient, quieter and more environmentally friendly technology designed at low cost and short time scales.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Possibilities to Improve Hydrodynamic Performances of Micro-Hydrokinetic Turbines

Barbarić

Guzović

2020

Energies

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Horizontal axis turbines are commonly used for harnessing renewable hydrokinetic energy, contained in marine and river currents. In order to encourage the expansion of electricity generation using micro-hydrokinetic turbines, several design improvements are investigated. Firstly, optimization-based design of rotor blade is used to get as close as possible to the efficiency limit of 59.3% (known as Betz limit), that counts for bare turbine rotors, placed in the free flow. Additional diffuser elements are further added to examine the potential to overcome the theoretical efficiency limit by accelerating water at the axial direction. Various diffuser geometrical configurations are investigated using the computational fluid dynamics (CFD) to obtain insight into hydrodynamics of augmented micro-hydrokinetic turbines. Moreover, the turbines are compared from the energy conversion efficiency point of view. The highest maximum power coefficient increase of 81% is obtained with brimmed (flanged) diffuser. Diffusers with foil-shaped cross-sections have also been analyzed but power augmentation is not significantly greater than in the case of simple cross-section designs of the same dimensions. The power coefficients’ comparison indicate that considerable power augmentation is achievable using brimmed diffuser with higher value of length-to-diameter ratio. However, the impact of diffuser length increase on the power coefficient enhancement becomes weaker as the length-to-diameter ratio reaches a value of 1.

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Section: Introductionmentioning

confidence: 99%

Investigation of the Possibilities to Improve Hydrodynamic Performances of Micro-Hydrokinetic Turbines

Barbarić

Guzović

2020

Energies

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“…En A05 Riglin et al [15] realizan el análisis numérico de una turbina micro hidrocinética horizontal adecuada con dos diferentes diseños de difusor por medio de CFD, el modelo utilizado fue el de transporte de esfuerzo cortante k-ω, y como resultado del análisis realizado, se encontró un aumento en la potencia mecánica de salida del 39.5% y 55.8% en comparación con el rendimiento de la turbina no aumentada con difusor Los dos difusores analizados tenían una relación de área de 1.36 y 2.01. A medida que la relación de área aumenta de 1.36 a 2.01 el empuje total experimentado por la unidad aproximadamente se duplica.…”

Section: Transporte De Esfuerzo Cortante K-ω Para Solución De Ecuaciounclassified

“…Cómo variables de entrada se tienen el factor de potencia, la potencia y la velocidad del fluido y cómo variables de salida a partir del análisis numérico, se obtienen las dimensiones constructivas óptimas de la turbina. El método aplicado en este estudio es el de los volúmenes finitos, el cual es el método que internamente utiliza Ansys para los análisis CFD [15].…”

Section: Transporte De Esfuerzo Cortante K-ω Para Solución De Ecuaciounclassified

“…[27] se pudo observar que para una turbina híbrida: Darrieus-Savonious, el coeficiente de potencia tiene un valor máximo para valores de ángulos de ataque de 30° y 60° con una relación de radio de 0.2. Otra característica relevante que se puede obtener de los estudios numéricos recopilados es la adecuación de turbinas aumentadas con difusor y la influencia de esta adecuación en el desempeño de la turbina, dónde se evidencia que al acoplar el difusor a la turbina se obtienen mejores desempeños o coeficientes de potencia como lo reportan Riglin et al [15].…”

Section: ¿Qué Variables Implícitas En El Desarrollo De Turbinas Hiunclassified

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Métodos numéricos para el desarrollo de una turbina hidrocinética tipo Gorlov

Pineda-Ortiz¹,

Chica²

2020

revuin

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Actualmente, a nivel mundial las energías alternativas han tomado gran importancia en las diversas aplicaciones relacionadas con el desarrollo del sector energético, entre las cuales podemos mencionar la energía solar, eólica, hidráulica, geotérmica y mareomotriz. Una nueva tecnología que aprovecha la energía cinética de la corriente de agua en canales naturales y/o artificiales e inclusivede las corrientes marinas son las turbinas hidrocinéticas. En este trabajo, se presenta un estudio de los diferentes métodos numéricos que pueden ser de utilidad para diseñar, analizar y optimizar sistemas de generación energética a partir de turbinas hidrocinéticas.

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“…The free surface can result in substantially adverse conditions, including vibration and performance reductions, when hydrokinetic turbines are operated in close proximity. The work done by Schleicheret al (2013Schleicheret al ( , 2015 and Riglin et al(2013Riglin et al( , 2014Riglin et al( , 2015 for hydrokinetic river application assumes that the depth of the river is variable in both time and space and that the depth is a critical design limitation necessary for broad application. As determined through data provided by the United States Geological Survey (USGS) regarding river freestream velocities and average depths, many rivers in the United States have approximately two to three meters of average depth or less.…”

Section: Introductionmentioning

confidence: 99%

Characterization of a micro-hydrokinetic turbine in close proximity to the free surface

et al. 2015

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Predicting hydrokinetic turbine power generation is difficult due to complex geometry, highly turbulent conditions, and difficulty capturing the transient interface existing between air and water.A threedimensional finite volume solver was used to capture the effects resulting from free surface interaction with the aid of a Volume of Fluid(VOF) multiphase solver.Depths from free surface level to blade tip with corresponding Froude numbers of 0.71, 0.92, 1.04, and 1.31 were modelled specifically to capture the transition from subcritical to supercritical flow conditions.A sharp decrease in performance was observed at the critical Froude number (Fr=1.0).Results at subcritical conditions showed acceptable agreement with previously published single phase results where the turbine is assumed to be operating in aninfinite medium.At subcritical conditions, the propeller-based turbine studied was compared to numerical and experimental results obtained for a traditional marine current turbine (MCT).As the flow became critical, a 32.2% decrease in the power coefficient was predicted and significant wake-free surface interaction was observed.

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Numerical analysis of a shrouded micro-hydrokinetic turbine unit

Cited by 16 publications

References 13 publications

Investigation of the Possibilities to Improve Hydrodynamic Performances of Micro-Hydrokinetic Turbines

Investigation of the Possibilities to Improve Hydrodynamic Performances of Micro-Hydrokinetic Turbines

Métodos numéricos para el desarrollo de una turbina hidrocinética tipo Gorlov

Characterization of a micro-hydrokinetic turbine in close proximity to the free surface

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