The surge-heave-pitch coupling motions of the Φ-type vertical axis wind turbine supported by the truss Spar floating foundation

This paper studies the dynamic characteristic of the truss Spar-type floating foundation used to support the offshore vertical-axis wind turbine (VAWT). The effects of changes in foundation structural parameters on its motions were evaluated. The results show that radius of the buoyancy tank, radius of the upper mechanical tank, interval of the center of gravity and center of buoyancy, and height of the upper mechanical tank have important effects on the heave and pitch motions of the foundation. Two sets of foundation parameters (FS-1 and FS-2) were selected to support the 5 MW Darrieus wind turbine. The motion performances of the two floating VAWTs, S-1 (the VAWT supported by FS-1) and S-2 (the VAWT supported by FS-2), were analyzed and compared. It was observed that the amplitudes of the heave and pitch motions of the floating VAWT depend on the wave loads; the mean values of the heave and pitch motions depend on the aerodynamic loads. The floating VAWT S-2 had better motion performance; its heave and pitch motions were all small. The heave frequencies of the floating VAWT were equal to the wave frequencies. For the pitch frequencies, there is a component of the rotor rotational frequency (0.175 Hz) for cases LC1 to LC4, while the amplitudes of the twice-per-revolution (2P) response are far smaller than the amplitudes of the wave response.

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Motion Performances of a 5 MW VAWT Supported by Spar Floating Foundation With Heave Plates

Volume 10: Ocean Renewable Energy ◽

10.1115/omae2017-62625 ◽

2017 ◽

Cited By ~ 1

Author(s):

Liqin Liu ◽

Ying Guo ◽

Weichen Jin ◽

Rui Yuan

Keyword(s):

Wind Turbine ◽

Large Scale ◽

Vertical Axis ◽

Offshore Wind ◽

Vertical Axis Wind Turbine ◽

Motion Equations ◽

Offshore Wind Power ◽

Floating Foundation ◽

Motion Study ◽

Truss Spar

The VAWT (vertical axis wind turbine) has advantages in the development of large-scale offshore wind power. This paper presents a motion study of a 5 MW floating VAWT composed of the Φ type Darrieus wind turbine and a truss spar floating foundation with heave plates. The surge, heave and pitch motion equations considering the effects of retardation function of the floating VAWT were established and solved numerically. Several load cases were carried out to analyze the motion performances of the floating VAWT. The results show that the wind forces have minimal influence on the heave motions of the floating VAWT, while they obviously increase its surge and pitch mean displacements. For LC3, the surge, heave and pitch frequencies of the floating VAWT are dominated by the wave frequencies, and the 2P (twice-per-revolution) response of pitch motions is not significant. For LC4, the 2P response of pitch motions of the floating VAWT are more significant than LC4.

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Study on the Hydrodynamic Characteristic of a Spar Type Floating Foundation Which Used to Support a Vertical Axis Wind Turbine

Volume 6: Ocean Space Utilization; Ocean Renewable Energy ◽

10.1115/omae2016-54337 ◽

2016 ◽

Cited By ~ 1

Author(s):

Liqin Liu ◽

Xiaorui Zhang ◽

Ying Guo ◽

Yu Qiu

Keyword(s):

Wind Turbine ◽

Large Scale ◽

Hydrodynamic Characteristic ◽

Vertical Axis ◽

Offshore Wind ◽

Initial Structure ◽

Vertical Axis Wind Turbine ◽

Natural Period ◽

Ballast Tank ◽

Floating Foundation

The vertical axis wind turbine has more advantages in the development of the large-scale offshore wind power, on account of that its drive system is placed on the bottom of the turbine and has little influence on the tower. This paper presents a preliminary design of a Spar foundation, which can support a Darrieus vertical axis wind turbine with a generated power of 5 MW. The influences of structure’s parameters of the floating foundation, such as the radius of flotation tank, the radius and height of upper ballast tank, the height of bottom ballast tank and other factors on the motions of the floating wind turbine system are analyzed. The initial structure parameters of the floating foundation are determined, and the hydrodynamic parameters are calculated as well. It is found that the radius of floatation tank and bottom ballast tank have more impact on the Response Amplitude Operators (RAOs) and natural period of heave of the floating foundation. The interval of center of gravity and center of buoyancy and the height of upper ballast tank influence obviously on the RAOs and natural period of pitch of the floating foundation. Heave and pitch motions of the floating foundation designed here are relatively small. The natural periods of heave and pitch of the floating foundation are away from the main wave energy periods.

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Vertical-Axis Wind Turbine Blade-Shape Optimization Using a Genetic Algorithm and Direct-Forcing Immersed Boundary Method

Journal of Energy Engineering ◽

10.1061/(asce)ey.1943-7897.0000741 ◽

2021 ◽

Vol 147 (2) ◽

pp. 04020091

Author(s):

Ming-Jyh Chern ◽

Desta Goytom Tewolde ◽

Chao-Ching Kao ◽

Nima Vaziri

Keyword(s):

Genetic Algorithm ◽

Shape Optimization ◽

Wind Turbine ◽

Turbine Blade ◽

Immersed Boundary Method ◽

Vertical Axis ◽

Immersed Boundary ◽

Vertical Axis Wind Turbine ◽

Blade Shape ◽

Direct Forcing

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Calculating the aerodynamics of vertical axis wind turbines

Vietnam Journal of Mechanics ◽

10.15625/0866-7136/34/3/2358 ◽

2012 ◽

Vol 34 (3) ◽

pp. 169-184 ◽

Cited By ~ 1

Author(s):

Hoang Thi Bich Ngoc

Keyword(s):

Wind Turbine ◽

Incidence Angle ◽

Vertical Axis ◽

Rotor Blades ◽

Vertical Axis Wind Turbine ◽

Horizontal Axis Wind Turbine ◽

Velocity Triangle ◽

Relationship Of ◽

The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

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