1. Key Laboratory of High-Efficiency and Clean Mechanical Manufacture of MOE, National Demonstration Center for Experimental Mechanical Engineering, School of Mechanical Engineering, Shandong University, Jinan 250061, China
2. Research Institute of Shandong University, Rizhao 276800, China
3. CSSC Haizhuang Windpower Co., Ltd., Chongqing 401122, China
4. Institute of Engineering Thermal Physics, Chinese Academy of Sciences, Beijing 100190, China
5. Department of Mechanical Engineering, Kyunghee University, Yongin 449791, Republic of Korea