1. National Wind Institute, Texas Tech University, Lubbock, TX 79415, USA
2. Electric Power Research Institute, Palo Alto, CA 94304, USA
3. Department of Mechanical Engineering, Tribhuvan University, Dharan 56700, Nepal
4. Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79401, USA
5. Renewable Energy Program, Texas Tech University, Lubbock, TX 79401, USA