Author(s): M. A. A. Faruque; Partha Sarathi; Ram Balachandar
Linked Author(s): Ram Balachandar
Keywords: Jet scour; Nozzle size-to-grain size ratio; Turbulent bursts; Asymptotic state
Abstract: In this paper, the scour caused by a submerged square jets in cohesionless soils is discussed. Experiments were carried out at three different values of densimetric Froude number (3. 9 ≤ Fo ≤ 10), a range of tailwater conditions varying from low to very high submergence, and two different sand bed grain sizes. At a given densimetric Froude number, progressing from the start of the test towards asymptotic conditions, the geometric parameters used to describe scour are found to be sensitive to tailwater conditions and the ratio of the nozzle size-to-grain size. At a given tailwater depth, the scour geometry tended to increase with increasing densimetric Froude number. This effect was prominent at all tailwater depths. At low values of the relative tailwater depth, the flow and the corresponding scour pattern tends to be non-symmetrical. New equations describing the scour geometry are proposed for the asymptotic state. These relations are found to be valid for a wide range of test conditions.
Year: 2007