State-of-the-art in development of diffuser augmented wind turbines (DAWT) for sustainable buildings

In this paper, a review of the development of Diffuser Augmented Wind Turbines (DAWT’s) into the Built Environment has been presented. DAWT’s offer a lot of potential as electricity providers in areas where it is needed, such as in the built environment. Research into DAWT’s has revealed that flow along a building significantly affects inlet conditions to the rotor due to flow separation at the leading edge. Adjusting the area ratio, length/diameter ratio as well as diffuser design can improve the performance of the free-standing DAWT significantly. Placing the turbine at the centre of a roof is found to allow the best wind conditions to the wind turbine. It was found that a turbine can be placed at a height 1.3 times the height of a small building for the best results. It has been found that vaulted roof’s encourage acceleration of air flow better than other topologies. Furthermore, a recent approach to building-integrated wind turbines involves a flow-enhancing architectural design for buildings to improve favourable inlet conditions to a DAWT

Effects of built environment morphology on wind turbine noise exposure at building façades

© 2017 Elsevier LtdWith wind farms installed in urban and suburban areas, the noise exposure of buildings is affected both by distance attenuation and the morphology of the built environment. With the aim of exploring the noise-resisting effects of built environment morphology, three kinds of typical suburban areas in the UK were sampled and noise maps were generated based upon an idealised modern wind turbine placed at various setback distances from each site. Relationships between morphological indices and building façade exposures were examined through regression analyses. Noise reduction levels of five morphological indices were given in terms of resisting wind turbine noise with different source-receiver (S-R) distances, and at different frequencies. The results show that built environment morphology has considerable effects on resisting the noise exposure of buildings and can create a quiet façade with up to 13 dBA difference to the most exposure façade. Among the five indices, building orientation is found to be most effective in resisting the noise exposure of building façades, followed by the length and shape of the building. The noise resistance effects vary by different S-R distances and differ by frequency. Four morphological indices are found to be effective in resisting noise at low frequencies, typically at 50 Hz