1. Institute of Fluid Mechanics and Fluid Machinery, Rhineland-Palatinate Technical University 1 , 67663 Kaiserslautern, Germany
2. Research Center of Fluid Machinery Engineering and Technology, Jiangsu University 2 , Zhenjiang 212013, China
3. College of Hydraulic Science and Engineering, Yangzhou University 3 , Yangzhou 225009, China