مشخصات پژوهش

In this paper the analysis of scouring has been analyzed, which usually takes place in river bends at high speeds. River’s spur dikes are considered as important organizing structures o f rivers. Spur dikes are cross-over structures whic h expand from river bank to flowing axis and deflect or direct flow to river’s central axis. The spur dikes are formed individuall y or in subsequent series in one or both sides of the river. In this paper, the anal ysis of the flow speed and scouring around T-shaped spur dike at 90 degrees arc, have been considered. A three-phase flow simulation of air, water and sediment was used based on the V OF model via fluent and flow-3D software’s. Using these software’s, scourin g phenomenon was examined for three different volum e rates. Observations suggested the spur dike affected topography of the arc bed due to the flow pattern of the secondary fl ow and formation of another secondary flow in the opposite direction of the mai n secondary flow. Results clearly showed that as th e volume rate goes up, the scour rate in the external arc and sedimentation ra te in internal arc increases. Results also revealed that in a no-spur dike in the arc, scouring rate was five times more than when there w as a spur dike.