Experimental Study of Radius of Curvature Influence On Density Current Behavior in 90 Degree Bend

   A density current is a (two-phase) flow of a fluid of density which is caused essentially by the influence of a density difference on the gravity. The previous experimental studies have been focused on investigation into properties of gravity current in straight channels. This paper presents a series of experiments in which saline gravity currents flowed through in physical models laboratory of Shahid Chamran University of Ahvaz. Experiments were carried out in 8.5 m length, 20cm width and 70cm height of flume and three radiuses of curvature (40, 80,120 cm). In this study the effect of three radiuses of curvature of channel bends on density flow behavior were studied. Experiments performed by four discharges (0.5,0.7,0.9 and 1.1 L/s) and four concentrations (8, 12, 16, 20 and 40 g/L). An Acoustic Doppler velocimeter (ADV-Vectrino⁺) was used to record the instantaneous downstream velocity. The Vectrino Velocimeter measures water speed using the Doppler effect. The results show that the elevation of the interface at the outer bank is in every case greater than the one at the inner bank. The results show that due to increasing the relative radius of channel bend decreases elevation of the interface and transverse interfacial slopes. The maximum and minimum superelevation occur in r/b =2 and r/b=6, respectively.