WiSE Research Spotlight: Dr. Stephen Ekwaro-Osire

In the U.S., wind energy is the one of the electrical energy sources that is growing fastest. The growth has been linear at a rate of about 20% to 30% per year over the last decade. The U.S. Energy Information Administration estimates that U.S. electricity demands 39% increase by 2030. This led to a collaborative effort to explore a modeled energy scenario in which wind provides 20% of U.S. electricity by 2030. The 20% Wind Scenario would require delivery of nearly 1.16 billion MWh of wind energy in 2030. Also, the 20% Wind Scenario project will offer potentially positive impact, such as avoiding air pollution, reducing electric sector CO2 emissions by 825 million metric tons annually, reducing water consumption for electric sector by 8% and generating new income source for local and federal economies.

However, various obstacles still remain to attain the goal of the 20% Wind Scenario project. One of the most serious problems is the reliability of wind turbines as gearbox failure has been a major problem in the wind industry. Compared to the other wind turbine components, gearbox failures result in among the highest down time per failure. In addition, a new gear design is needed due to the increasing performance requirements. Recently, theoretical analyses have shown that asymmetric gears may offer a potential to reduce the costs associated with the gear failures. Also, the wind turbine gears experience only uni-directional loading and the geometry of the drive side does not have to be symmetric to the coast side. This allows for the designing of gears with asymmetric teeth.

The objective of this research is to design and construct an experimental system for testing the performance of asymmetric gears. This experiment investigation provides a unique opportunity to address the interplay between theory and experiments. Another major objective of this project is to develop a new gear design used in wind turbine gearbox. This research will propose a novel asymmetric gear design that increases the reliability of wind turbine gearbox. The research accomplishments are expected to contribute for wind industry to save millions of expenditure related to gearbox failures and repairing cost of the gearboxes.

(Above) Post-Doctoral Research Associate Dr. Taek H. Jang works on the experimental gear box at the WiSE research facilities at Reese.

Credit: Dr. Stephen Ekwaro-Osire, Professor, and Dr. Taek H. Jang, Post-Doctoral Research Associate, Department of Mechanical Engineering, TTU.

For more information on this research, click Dr. Stephen Ekwaro-Osire