Search

Small Wind Turbines (SWTs) are an increasingly developing Renewable Energy Source, thanks to the gradual popularisation of the prosumer energy generation approach. This, however, requires maximum safety of the machine, working next to households. Reliability is also necessary from the financial point of view, as SWTs should withstand 20 - 30 years of operation without any serious failure to ensure investment profitability. The weakest SWT element is arguably its most exposed one - the rotor - hence the important role played by the blade strength tests. The experimental analysis becomes preferable with increasing popularity of new materials (composites) and production techniques (additive manufacturing). This paper sets out to develop a test stand for static strength examination of 3D-printed SWT blades. This kind of objects is often considered as more vulnerable to structural failures than those created via machining techniques, due to their anisotropic structure, so ensuring structural integrity is crucial for safety reasons.

Increasing popularity of individualised electricity generation from wind by prosumers creates a strong demand for profitable and highly efficient small wind turbines. This paper investigates the influence of rotor blade solidity parameter on device efficiency in hope of determining its optimal value as a part of the development process of the GUST small wind turbine. The study involved experimental analysis in the wind tunnel and numerical simulations performed in QBlade software. Different solidities of the rotor were achieved by alteration of (1) number of blades and (2) chord distribution along the blade span. The increase of rotor solidity resulted in augmentation of the aerodynamic efficiency in both approaches. The elongation of the chord by 33% in a 3-bladed rotor resulted in a bigger power coefficient increment than addition of a 4th blade with original chord distribution. Even though the solidity was the same, the 3-bladed rotor performed better, possibly due to lower form drag. The results emphasize the importance of the rotor solidity optimization during the small wind turbine rotor development and may significantly influence overall power output.