1. Ph.D. Student, Technical Univ. of Denmark, Dept. of Mechanical Engineering, Section of Fluid Mechanics, Coastal and Maritime Engineering, DK-2800 Kongens, Lyngby, Denmark (corresponding author).
2. Associate Professor, Technical Univ. of Denmark, Dept. of Mechanical Engineering, Section of Fluid Mechanics, Coastal and Maritime Engineering, DK-2800 Kongens, Lyngby, Denmark.
3. Professor Emeritus, Technical Univ. of Denmark, Dept. of Mechanical Engineering, Section of Fluid Mechanics, Coastal and Maritime Engineering, DK-2800 Kongens, Lyngby, Denmark.