| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 264389 | Energy and Buildings | 2011 | 8 Pages |
Rotating wind driven turbine ventilator has been used as cost-effective environmental friendly natural ventilation device. Rotating wind driven turbine ventilator type of device is usually installed on the rooftop to extract air extract air flow from a building to improve air quality and comfort. Performance investigations carried thus far on turbine ventilator have ignored the effect of the inclination on rooftop. An experimental program was, therefore, formulated at the aerodynamic laboratory of the University of New South Wales to study such effect on a simulated rooftop. The results obtained from the measured forces and rotational speeds on different configurations indicate that the effect is minimal in extracting air from a building at low wind speed. The static pressure and skin friction distributions on the simulated roof further supports this finding. Two important conclusions can be drawn from the present investigation: firstly, the presence of the inclined roof may extend the safety margin in the operation of a turbine ventilator at high wind speed by reducing the magnitude of the total force that acts on the ventilator; secondly the dependency of the total fore on low Reynolds number suggests that the efficiency and reliability of operation of such ventilator should be boosted through the provision of other power source such as solar power at low wind speed.
Research highlights▶ The forces acting on the ventilator and its rotational speed were found to have a linear increasing trend with the free stream velocity. ▶ The total force acting on the ventilator as well as its rotational speed decrease with the increase in inclination angle and the effect is more pronounced at higher wind speeds. ▶ The effect of inclined roof on the performance of a rotating turbine in extracting air from a building appears to be minimal. ▶ The presence of inclined roof may be used to extend the margin of safety in the operation of a wind driven turbine ventilator by reducing the magnitude of the total force that acts on the ventilator at higher wind speed. ▶ The efficiency and reliability of a ventilator operation may require boosting by a hybrid system that incorporates other power source such as solar power to overcome the inertia and friction forces acting on the body to initiate ventilator rotation at lower wind speed.
