| Abstract |
In this paper, we discuss the ongoing work about setting up of a smart turbine energy harvester (STEH) based on the aerodynamics of vortex-induced vibration (VIV) of a home-chimney external cap; pinwheels (HCP), and its adaptation to generate electricity. In this research, the pinwheels meant to serve as external cap to home chimney exhaust outlet is converted to vertical axis wind turbine, and the fluid-structure dynamism and generated output voltage when wind is at low and moderate speeds are investigated. The HCP-STEH unlike the large scale vertical axis wind turbine (VAWT) or horizontal axis wind turbine (HAWT) generators is of very low inertia, which makes it to continue to spin effortlessly on rooftops at the slighted provocation of wind energy. This aerodynamic vorticity of the pinwheels is made to serve as source of mechanical vibration to a connected brush-less fan; which in this case is used as the electromagnetic converter (dynamo) meant to pump electromotive force (emf) through the set-up. In the setup, the dynamo is mechanically fastened to the pinwheels circular base through a harness, and the rotation of the pinwheels is transmitted to the dynamo by contact friction. In experiments, the HCP-STEH was investigated as a VIV set-up with low and moderate wind speeds. Results show that peak output voltage of 1.31.7V was realised at no load, for a speed of between 7.05 and 7.4 km/hr., with tremendous increase in peak output voltage up to about 16V at around wind speed of 16 km/hr. The behaviour of the generated output voltage with wind speed was modeled and the model revealed a limiting output voltage of about 20V with much increased speed and minimum operational wind speed of about 6.8 km/hr. This becomes an energy harvester which can be powered by mechanical vibration of bluff-body using wind energy at 16 km/hr; which is the average wind speed of the environment in real life applications. This is sufficient to operate low power Internet of Things (IoT) nodes deployed around the city for environmental monitoring and autonomous purposes. Therefore, in this manner, pinwheels home-chimney exhaust ventilator caps are converted to 'stand-alone' low cost smart turbine energy harvesters, with no battery attached, and no grid connection, and they can be installed as attachments to IoT nodes or in close proximity to other points of consumption. |
