On the actual power coefficient by theoretical developing of the diffuser flange of wind-lens turbine

Heikal, H.; Abu-Elyazeed, Osayed Sayed Mohamed; Nawar, Mohamed A.A.; Attai, Youssef A.; Mohamed, Maged M.S.

doi:10.1016/j.renene.2018.02.100

Cited by 41 publications

(20 citation statements)

References 27 publications

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“…Heikal et al [16] studied the power coefficient (C P ) of a ducted wind turbine with numerical simulations. They reported a power factor of 90% for some wind speeds.…”

Section: Introductionmentioning

confidence: 99%

Power Enhancement of a Vertical Axis Wind Turbine Equipped with an Improved Duct

et al. 2021

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Efforts to increase the power output of wind turbines include Diffuser Augmented Wind Turbines (DAWT) or a shroud for the rotor of a wind turbine. The selected duct has three main components: a nozzle, a diffuser, and a flange. The combined effect of these components results in enriched upstream velocity for the rotor installed in the throat of the duct. To obtain the maximum velocity in the throat of the duct, the optimum angles of the three parts have been analyzed. A code was developed to allow all the numerical steps including changing the geometries, generating the meshes, and setting up the numerical solver simultaneously. Finally, the optimum geometry of the duct has been established that allows a doubling of the flow velocity. The flow characteristics inside the duct have also been analyzed in detail. An H-Darrieus Vertical Axis Wind Turbine (VAWT) has been simulated inside the optimized duct. The results show that the power coefficient of the DAWT can be enhanced up to 2.9 times. Deep dynamic stall phenomena are captured perfectly. The duct advances the leading-edge vortex generation and delays the vortex separation.

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“…Heikal et al [16] studied the power coefficient (C P ) of a ducted wind turbine with numerical simulations. They reported a power factor of 90% for some wind speeds.…”

Section: Introductionmentioning

confidence: 99%

Power Enhancement of a Vertical Axis Wind Turbine Equipped with an Improved Duct

et al. 2021

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“…Entre las diferentes opciones de concentradores de flujo para turbinas eólicas, existe un modelo particular llamado wind lens (WL), que ofrece beneficios como incremento en la potencia de salida (Clements, & Chowdhury, 2019;Heikal, et al, 2018), control de la orientación de la turbina por el anillo del mismo WL (Ohya, & Karasudani, 2010), reducción de ruido (Ohya, Karasudani, Nagai, & Watanabe, 2017;Takahashi, Hata, Ohya, Karasudani, & Uchida, 2012) y mejora en la seguridad (Khamlaj, & Rumpfkeil, 2018). Además, el WL es más amigable con las aves que las turbinas convencionales como se aprecia en ; lo que lo hace atractivo para su uso en zonas boscosas que, de acuerdo con SAGE Journals (2006), poseen bajo potencial eólico y alta turbulencia.…”

Section: Introductionunclassified

“…Con el fin de caracterizar el efecto del WL, existen en estudios del flujo a través del propio WL sin presencia de la turbina, donde se aprecia cómo se concentran las líneas de flujo (Heikal, et al, 2018;Khamlaj, & Rumpfkeil, 2018;Maftouni, & Parsa, 2019;Nasution, & Purwanto, 2011;Ohya, & Karasudani, 2010); sin embargo, no ha sido reportado el caso de mediciones de la velocidad del viento en un campo de flujo turbulento con el WL y sin este, para evaluar el efecto de este concentrador en condiciones de turbulencia.…”

Section: Introductionunclassified

Efecto de un difusor tipo wind lens en flujo turbulento

2021

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El objetivo fue medir el efecto de un concentrador de flujo tipo wind lens en el caso de flujo turbulento. El estudio se realizó en el túnel de viento de capa límite del Instituto de Investigación en Mecánica Aplicada de la Universidad de Kyushu, Japón, entre marzo y mayo de 2019. Se utilizó un anemómetro de hilo caliente con un mecanismo móvil para realizar tres pruebas. Primero se mide la velocidad en el eje del túnel, sin la rejilla de turbulencia instalada. En segundo lugar, se coloca la rejilla y se mide la intensidad de turbulencia en el eje del túnel de viento. En tercer lugar, se determina el efecto del WL en la velocidad del viento incidente, a diferentes niveles de intensidad de turbulencia. La velocidad del viento en el túnel sin la rejilla de turbulencia es casi constante, alrededor de 9.6 m/s. Al colocar la rejilla se registró en el eje del túnel de viento una intensidad de turbulencia decreciente, desde un valor de 28.6 % a 500 mm de la rejilla, hasta un 5 % de intensidad de turbulencia a 3 100 mm de la rejilla. Cuando se midió el efecto del wind lens en flujo turbulento, se obtuvo un aumento del 20 % o más en la velocidad del viento. El wind lens demostró ser adecuado para turbinas eólicas que operan en flujo turbulento, acrecentó la velocidad del viento en todas las pruebas, generando un mayor aumento a mayor intensidad de turbulencia.

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“…Experimental results showed that the blade rotation speed increased by 1.35 times with the equipment of a flanged diffuser as compared to the same wind turbine without a diffuser, which resulted in a higher level of strain at the blade root during rotation. Recent numerical researches have been carried out to investigate the diffuser geometry, including the flange inclination angle and cylinder shape on the performance of DAWT, and achieved the maximum power augmentation by 14-28% [19,20].…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical study of the novel diffuser with a passive adaptive flexible flange for improving the shroud augmented wind turbine

Zhou

et al. 2020

IET Renewable Power Generation

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This study proposed a new type of diffuser which can not only accelerate the wind approaching the turbine before wind velocity reaches the rated velocity, but also reduces the wind drag on the diffuser when wind velocity is overrated one. A passive adaptive flexible flange constructed of two flexible cantilevered plates is developed for the diffuser. The flow distribution around the diffuser equipped with a flexible flange, as well as the wind drag on the diffuser, varies with the deformation of the flexible flange under the wind drag. Wind tunnel experiments and numerical analysis are conducted to study the flow distribution around the diffuser and the corresponding wind drag on it at different wind velocities. Experimental results reveal that the drag reduction rate of the diffuser with the passive adaptive flexible flange is 17.9% at the velocity of 20 m/s. Numerical results overall match well with the experimental measurement, such as velocity and pressure distributions, although the simulated values are slightly lower than the experimental ones.

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On the actual power coefficient by theoretical developing of the diffuser flange of wind-lens turbine

Cited by 41 publications

References 27 publications

Power Enhancement of a Vertical Axis Wind Turbine Equipped with an Improved Duct

Power Enhancement of a Vertical Axis Wind Turbine Equipped with an Improved Duct

Efecto de un difusor tipo wind lens en flujo turbulento

Experimental and numerical study of the novel diffuser with a passive adaptive flexible flange for improving the shroud augmented wind turbine

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