1. Professor, Hydraulics Laboratory, Dept. of Civil Engineering, Aristotle Univ. of Thessaloniki, 54124 Thessaloniki, Greece.
2. CFD Engineer, SimTec Ltd., 2 P. P. Germanou St., 54622 Thessaloniki, Greece.
3. Research Assistant, Hydraulics Laboratory, Dept. of Civil Engineering, Aristotle Univ. of Thessaloniki, 54124 Thessaloniki, Greece.