1. Chair of Hydro and Aeromechanics, Dept. of Mechanics, Faculty of Civil Engineering, Tallinn Univ. of Technology, Ehitajate 5, Tallinn 19086, Estonia (corresponding author).
2. Chair of Hydro and Aeromechanics, Dept. of Mechanics, Faculty of Civil Engineering, Tallinn Univ. of Technology, Ehitajate 5, Tallinn 19086, Estonia.