Experimental Study of Mobile Bed Influence on Density Current Behavior in Submarines

Subject Areas : Subjects

marzieh mohamadi ghanatghestani ¹ (Ph.D. of Water Structure, College of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran)
mehdi ghomeshi ² (Prof. of Hydraulic Structures, College of Water Sciences Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran)

Received: 2020-07-19 Accepted : 2022-01-19 Published : 2022-01-21

Keywords: Velocity profile, density current, Mobile Bed, Relative of Radius of Curvature, Super Elevation,

Abstract :

Basically, dense flow is a two-phase flow that occurs due to the movement of a fluid in a different fluid of different densities. Laboratory research has been carried out on physical and hydraulic models of the Faculty of Engineering Sciences of Shahid Chamran University of Ahwaz. Flume contains three successive bends with three different relative curvature radiuses: r/b=2, 4 and 6, 8.5 m length, 20cm width and 70cm height and a mobile bed type of Polyastailen cover the bed. The results show, increasing the concentration of the inlet current, the flow velocity of the body flow increases on a mobile bed. The rate of increase in velocity depends on changes in the form of the bed the flow rate of the body will be reduced to about 19%. The velocity of the forehead has increased in the conditions of the mobile bed by forming the form of the bed. Also the elevation of the interface at the outer bank is in every case greater than the one at the inner bank. Due to increasing the relative curvature radius decreases elevation of the interface and transverse interfacial slopes. The maximum and minimum super elevations occur in r/b =2 and6, respectively. the transverse velocity decreases and the velocity increases in direct direction, which plays a significant role in reducing the slope of the water surface and the difference in height. Hence, the difference between the level of water in the third arc is very small.

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