Prediction of Scour Profile Caused by Submerged Three-Dimensional Wall Jets

Series of laboratory tests were carried out to study the
extent of scour caused by a three-dimensional wall jets exiting from a
square cross-section nozzle and into a non-cohesive sand beds.
Previous observations have indicated that the effect of the tail water
depth was significant for densimetric Froude number greater than ten.
However, the present results indicate that the cut off value could be
lower depending on the value of grain size-to-nozzle width ratio.
Numbers of equations are drawn out for a better scaling of numerous
scour parameters. Also suggested the empirical prediction of scour to
predict the scour centre line profile and plan view of scour profile at
any particular time.

• Abdullah Al Faruque
• Ram Balachandar

• Densimetric Froude Number
• Jets
• Nozzle
• Sand
• Scour
• Tailwater
• Time.

[1] Faruque, M. A. A., Sarathi, P., and Balachandar, R. (2006). “Clear water
local scour by submerged three-dimensional wall jets: Effect of tailwater
depth.” Journal of Hydraulic Engineering, 132(6), 575-580.
[2] Rajaratnam, N. (1981). “Erosion by plane turbulent jets.” Journal of
Hydraulic Research, Vol. 19, No. 4, pp.339-358.
[3] Ade, F. and Rajaratnam, N. (1998), “Generalized study of erosion by
circular horizontal turbulent jets”, Journal of Hydraulic Research, Vol.
36, No. 4, pp.613-635.
[4] Ali, K. H. M., and Lim, S. Y. (1986). “Local scour caused by submerged
wall jets.” Proc. of the Instn. of Civil Engrs., Part 2, 81, pp.607-645.
[5] Lim, S. Y. (1995). “Scour below unsubmerged full-flowing culvert
outlets.” Proc. of the Institution of Civil Engineers, Water Maritime and
Energy, Vol. 112, pp.136-149.
[6] Rajaratnam, N., and Diebel, M. (1981). “Erosion below culvert-like
structures.” Proc., 5thCanadianHydrotechnical Conf., May26–27,
Canadian Society for Civil Engineering (CSCE), pp.469-484.
[7] Rajaratnam, N. and Macdougall, R.K. (1983), “Erosion by plane wall
jets with minimum tailwater”, Journal of Hydraulic Engineering, Vol.
109, No. 7, pp.1061-1064.
[8] Chiew, Y.M. and Lim, S.Y. (1996), “Local scour by a deeply submerged
horizontal circular jet”, Journal of Hydraulic Engineering, Vol. 122, No.
9, pp.529-532.
[9] Aderibigbe, O., and Rajaratnam, N. (1998). “Effect of sediment
gradation on erosion by plane turbulent wall jets.” Journal of Hydraulic
Engineering, Vol. 124, No. 10, pp.1034-1042.
[10] Rajaratnam, N., and Berry, B.(1977). “Erosion by circular turbulent wall
jets.” Journal of Hydraulic Research, Vol. 15, No. 3, pp.277-289.