The Diffuser Augmented Wind Turbines (DAWTs) have been widely studied, since the diffusers improve the power coefficient of the wind turbine, particularly of small systems. The diffuser is a device which has the function of causing an increase on the flow velocity through the wind rotor plane due to pressure drop downstream, therefore resulting in an increase of the rotor power coefficient. This technology aids the turbine to exceed the Betz limit, which states that the maximum kinetic energy extracted from the flow is 59.26%. Thus, the present study proposes a mathematical model describing the behavior of the internal velocity for three conical diffusers, taking into account the characteristics of flow around them. The proposed model is based on the Biot-Savart's Law, in which the vortex filament induces a velocity field at an arbitrary point on the axis of symmetry of the diffusers. The results are compared with experimental data obtained for the three diffusers, and present good agreement.

Educação e gestão ambiental no desenvolvimento sustentável na mineração de ferro: aproveitamento de rejeitos para obtenção de materiais cerâmicos Education and environmental management in sustainable development in iron mining: taking waste for ceramic materials

The use of diffusers around of the horizontal-axis wind turbines have been widely studied, since the diffuser provides an improvement in the turbine power coefficient. These diffusers are often called Diffuser Augmented Wind Turbines (DAWT’s). The DAWT’s have the feature to make efficiency exceeding the Betz limit (maximum energy flow extracted = 59.26%), due to the increasing of the internal mass flow by influence of the diffuser presence. Thus, the present work proposed a mathematical model describing the behavior of the velocity profile internally to a diffuser according to the characteristics of flow and geometry of a conical diffuser. The model results were compared with experimental data and showed good agreement.

Reaproveitamento de resíduos industriais como cargas em compósitos: resistência mecânica e à chamaReuse of industrial waste as loads in composites: mechanical and flame resistance

(CIP) M514 Meio Ambiente, sustentabilidade e tecnologia Sumário Capítulo 1: Descoloração do Azo corante alaranjado II usando biomassa e quitosana produzidas por Cunninghamella Phaeosphora em substratos agroindustriais ..