Abstract
In recent years, power generated by wind turbine has been gaining a lot of interest because of the growing concerns of climate change. Since power generated by wind turbine is proportional to the rotor size and the cube of the wind’s velocity, wind turbine has grown massive in size. To build these gigantic devices, large amount of capital needs to be invested. The challenge facing in the wind power world is to build an efficient device that minimizes the size and cost and maximizes the power output. A wind power technology that may be able to do this is the ducted wind turbine. A ducted wind turbine uses a ducted system to capture wind and increase its velocity, which enables the wind turbine to generate more electricity. One energy technology company, SheerWind, has developed a product called the INVELOX. This wind power-harnessing device is capable of capturing and increasing the wind’s kinetic energy. The company claimed that by utilizing their wind delivery device, the power output of a wind turbine inside this ducted system significantly outperforms a traditional wind turbine. This thesis analyzes the airflow in the INVELOX and assesses various design modifications to the original design to determine if the performance can be improved. In this thesis, the airflow in this wind delivery device is analyzed in a Computational Fluid Dynamic (CFD) modeling program called ANSYS Fluent (Version 15) to understand its flow characteristics. The solid geometry of the ducted wind turbine is created using a computer-aided design program called SolidWorks 2014. The analysis of the ducted wind turbine is important because the modeling results are compared to the results from a study for the INVELOX to establish a working and validated CFD model that will be used to evaluate the design modifications to the original design. Modeling results show that the use of this ducted system increases the wind speed by an average speed ratio of 1.58, which is consistent with the results in the study for the INVELOX. In addition, the results indicate that the omnidirectional intake of the ducted system did not work as designed. The ducted system is able to capture wind and increase the wind speed from some directions but not from all directions. Three modifications to improve the performance by increasing the wind speed passing over the wind turbine are made to the original design. These modifications are: 1) extending the four partitions into the ducted system, 2) enlarging the intake section, and 3) enlarging the intake section and extending the four partitions into the ducted system. With these modifications, the CFD modeling results show that the average velocity increases by up to 39% when compared to the average velocity of the original design. Furthermore, by using the actuator disk model in the CFD model to represent a wind turbine in the ducted system, the modeling results show that the modified ducted wind turbine systems are capable of generating more electricity than the original wind turbine design and a traditional wind turbine. As a result, the power outputs for the modified designs generate up to 220% more power than the original design and up to 754% more power than the traditional wind turbine. This thesis proves the original design for the ducted wind turbine works but the performance improvement is less than what was claimed by its manufacturer and uses a CFD modeling program to validate the results. Simple modifications to the intake section increase the wind speed inside of the duct and improve the performance of the ducted wind turbine.