نوع مقاله : مقاله پژوهشی
1 دانشجوی دکترای/ سازه های آبی دانشگاه شهید چمران اهواز
2 استادیار / گروه سازه های آبی دانشگاه شهید چمران اهواز
3 دانشیار / گروه سازه های آبی دانشگاه شهید چمران اهواز
4 استاد/ گروه سازه های آبی دانشگاه شهید چمران اهواز
عنوان مقاله [English]
Velocity and Entrainment of density current in the expansion reach where a river enters into a dam reservoir, a lake, or open sea is of utmost importance. The present study investigates the head velocity and entrainment of density currents in an Expansion Reach. The effects of discharge and bed slope on the head velocity and entrainment of the density current were evaluated by a physical and 3D mathematical model. Experiments were conducted in a flume, 6.0 meters long, 0.72 meters wide, and 0.6 meters in height. Head velocity was measured for an expansion degree of 8 in slopes of 0.0009 and 0.0016 for various discharges. Important parameters were normalized and a two-dimensional laser Doupler was used to develop the flow body velocity profile. The measurements showed that mixing values were higher in a divergent cross-section compared to a fixed cross-section. During some experiments a hydraulic jump was also detected depending upon the levels of the density current and slope of the bed in the divergent cross-section, which was investigated and the results are presented accordingly.