Sin Chew Poh

The development and testing of a novel cross axis wind turbine

A novel cross axis wind turbine (CAWT) which comprises of a cross axis blades arrangement was presented and investigated experimentally. The CAWT is a new type of wind turbine that extracts wind energy from airflow coming from the horizontal and vertical directions. The wind turbine consists of three vertical blades and six horizontal blades arranged in a cross axis orientation. Hubs in the middle of the CAWT link the horizontal and vertical blades through connectors to form the CAWT. The study used a 45° deflector to guide the oncoming airflow upward (vertical wind direction). The results from the study showed that the CAWT produced significant improvements in power output and rotational speed performance compared to a conventional straight-bladed vertical axis wind turbine (VAWT).

Performance Evaluation of a Wind Power-Augmented Device on an Onsite Exhaust Air Energy Recovery Wind Turbine

This paper presents an idea on generating green energy by extracting discharged wind energy from a cooling tower. Two vertical axis wind turbines (VAWTs) integrated with a wind power-augmentation device are installed above a cooling tower to harness unnatural wind for electricity generation. The wind power-augmentation device is built with several guide-vanes and diffuser-plates to improve the performance of the VAWTs. Guide-vanes are designed to create a venturi effect and guide the on-coming wind stream to an optimum flow angle which is matched to the optimum angle of attack of the VAWTs. Diffuser-plates are tilted at an optimum angle to draw more wind and accelerate the discharged airflow. From the laboratory test, the VAWTs performance was increased by 7 – 8 % when guide-vanes and diffuser-plates are installed at their optimum angle. The correct matching of VAWTs for this system is expected to generate electricity at their rated power constantly when the cooling tower is in operation. This system can contribute to the reduction of greenhouse gases emission and conservation of the environment for a healthier life since fossil fuel consumption for energy generation is reduced as well as efficient use of energy.

Experimental Investigation on the Moving-Air Path in Roof Models with Thermal Performances Evaluation

The indoor thermal comfort is the basic thing for each and every occupant, not only in tropical areas but also all over the world. It is necessary to make an energy efficient roof design and to improve the indoor condition of the building. This paper is focused on the roof design to develop the ventilation system so as to obtain low attic temperature without effecting the environment and keep the interior of the building cool. In the present study, four identical roof models were fabricated to carry out laboratory tests to evaluate their performances. In the roof models, aluminum (Al) tubes were used as a moving-air path (MAP) which acts as a ventilation channel. These channels allows the natural ventilation to take out hot air to the outside. In addition, an insulation layer and ventilation fans were integrated with the Al tubes to get better performance. For the combination of those features, the results revealed that the attic temperature was reduced remarkably, compared to the ordinary roof model. This comprehensive roof model will be the most suitable to the environment and applicable for its improved performance.