1. a IMAR-Institute of Marine Research, Department of Civil Engineering , University of Coimbra , Portugal
2. b Laboratoire des Ecoulements Géophysiques et Industriels/IMG, (Laboratoire de l'UJF, de l'INPG et du CNRS) , BP 53, 38041 Grenoble Cedex 9, France
3. c IMAR-Institute of Marine Research, Department of Civil Engineering , University of Coimbra , Portugal