A New Approach Toward Power Output Enhancement Using Multirotor Systems With Shrouded Wind Turbines

Abstract

A multirotor system (MRS) is defined as containing more than one rotor in a single structure. MRSs have a great potential as a wind turbine system, saving mass and cost, and showing scale ability. The shrouded wind turbine with brimmed diffuser-augmented wind turbines (B-DAWT) has demonstrated power augmentation for a given turbine diameter and wind speed by a factor of about 2–5 compared with a bare wind turbine. In the present research, B-DAWTs are used in a multirotor system. The power output performance of MRSs using two and three B-DAWTs in a variety of configurations has been investigated in the previous works. In the present study, the aerodynamics of an MRS with five B-DAWTs, spaced in close vicinity in the same vertical plane normal to a uniform flow, has been analyzed. Power output increases of up to 21% in average for a five-rotor MRS configuration are achieved in comparison to that for the stand-alone configuration. Thus, when B-DAWTs are employed as the unit of a MRS, the total power output is remarkably increased. As the number of units for an MRS is increased from two to five, the increase in power output becomes larger and larger. This is because that the gap flows between B-DAWTs in a MRS are accelerated and cause lowered pressure regions due to vortex interaction behind the brimmed diffusers. Thus, a MRS with more B-DAWTs can draw more wind into turbines showing higher power output.

Comportamiento de la intensidad de turbulencia en distintas áreas transversales en un túnel de viento

“…El panel 3 en el lado derecho (visto desde la dirección del flujo) está parcialmente removido. Esta configuración del túnel ha sido utilizada con éxito en investigaciones como [24] y [25].…”

Power Output Enhancement of a Ducted Wind Turbine by Stabilizing Vortices around the Duct

“…To eliminate the possibility of the blockage effect, the side walls and the ceiling panels of the test section were removed. This suppressed the blockage effect on the turbine in the tunnel [26]. Table 1 shows the experimental materials and conditions.…”

“…Accomplishing this goal will contribute substantially to growth of installed wind power capacity. this WLT concept to floating turbines [19,20], vertical axis wind turbines [21], and several types of multi-rotor systems [22][23][24][25][26] The duct of a WLT tends to enhance its flow augmentation with a longer diffuser or a higher brim [12,13], or both. A long-prototype diffuser (with a length 1.5 times that of the rotor diameter; see Figure 2a) exhibited five times larger power output than a bare turbine did with the same rotor diameter [12].…”

Efecto de un difusor tipo wind lens en flujo turbulento

“…El aprovechamiento de la energía del viento mediante turbinas eólicas presenta hoy en día una amplia variedad de opciones como lo son las turbinas tradicionales de eje vertical y horizontal, así como otras alternativas entre las que se pueden mencionar los postes oscilantes (El-Shahat, Hasan, & Wu, 2018); turbinas tipo tornillo (Jang, Kim, Hwang, Paek, Kim, & Baek, 2019); turbinas con una única superficie (Aouini, 2012); turbinas de eje horizontal que utilizan cilindros en vez de aspas (Richmond-Navarro, Calderon-Munoz, LeBoeuf, & Castillo, 2017); turbinas que aprovechan la convección debida a diferencias de temperatura (Watanabe, Fukutomi, Ohya, & Uchida, 2020), y turbinas con concentradores de flujo, las cuales alcanzan altos coeficientes de potencia (Keramat Siavash, Najafi, Tavakkoli Hashjin, Ghobadian, & Mahmoodi, 2020), pueden operar flotando en el agua (Zhu, Sueyoshi, Hu, & Yoshida, 2019), ofrecen beneficios de incremento de potencia en sistemas multirotor (Yuji, & Koichi, 2019) y aumentan la eficiencia aun en condiciones de baja velocidad de viento (Riyanto et al, 2019).…”