Effects of Aerodynamic Interactions of Closely-Placed Vertical Axis Wind Turbine Pairs

Abstract

In this study, a numerical model was developed to study the effects of aerodynamic interactions between a pair of counter-rotating vertical axis wind turbines (VAWTs) in close proximity. In this model, the rotor rotation is not prescribed as a constant as in most other studies, but is determined by the moment of inertia and the total torque of the rotor, including the aerodynamic torque, generator torque, and a torque representing friction. This model enables study of the behavior of the rotor under an arbitrary ambient wind profile. The model was applied to an isolated rotor with five straight J-blades and pairs of identical rotors placed in close proximity. Compared with an isolated rotor, the aerodynamic interactions between the pair of rotors enhance the aerodynamic torques on the rotors and significantly increase the turbine power output on a per unit basis. The enhancement in turbine power output due to aerodynamic enhancement decreases with the distance between the pair of rotors.

Varying VAWT Cluster Configuration and the Effect on Individual Rotor and Overall Cluster Performance

“…Some examples which use CFD to investigate the nature of VAWT wake characteristics are Samsoddin and Porte-Angel [15], who used a large eddy simulation approach for the investigation of wake characteristics behind a VAWT in a three-dimensional turbulent flow, and Bremseth and Duraisamy [7], who utilized the OVERTURNS solver and performed calculations using the solution of compressible URANS to simulate a single, paired, and array of VAWTs to conclude that a pair of counter-or co-rotating VAWTs were able to produce more power compared to an isolated turbine, taking advantage of the induced velocity field of the paired turbines. Peng [16], meanwhile, used OPENFOAM, open source CFD software utilizing the finite volume method, to compare the performance of two closely placed VAWT pairs and an isolated turbine. He concluded that the pairs of opposite-rotating turbines exhibit faster rotation compared with the isolated rotor in the same wind speed, hence a 70% performance improvement was noticed at a 1.6 equivalent turbine diameter spacing.…”

Review of Efficiency Improvement Technologies of Wind Diesel Hybrid Systems for Decreasing Fuel Consumption

“…Vergaerde et al (2019) experimentally showed that when two-bladed H-type Darrieus VAWT are installed next to each other in a plane normal to a uniform inflow, the power is increased by 16% compared to the output by two separate VAWT [105]. The closer the VAWT rotors are located, the stronger the effect is, which can reach nearly 70% at the rotor diameter to the distance between the rotors ratio d/D = 1.6 [106].…”