16
S. A. Majid and S. Tripathi
Fig. 3 Scour hole geometry along the length of channel for a different lengths and b different
degrees of contraction
4 Conclusions
The present study is based on the numerical simulations of the pressure flow scouring
due to vertical contraction in a flow passage. The scouring thus induced is a function
of the flow geometry and bed characteristics. However, the present study is restricted
to the flow geometry only. Other parameters like bed slope, flow depth, particle
diameter and the flow velocity are kept constant. It is observed that the bed shear
has the maximum value inside the contraction. For all the simulations, the scour
hole is observed to develop within the contraction towards the upstream face of the
contraction. The magnitude of maximum scour is a function of both the length of
the contraction and the degree of the contraction. The magnitude of maximum scour
increases with increase in degree of contraction or length of contraction or both. A
complete understanding of the pressure flow scour would require the inclusion of
the other flow and bed properties in the simulations and the validation of numerical
results with experimental observations.
References
1. Arneson LA, Abt SR (1998) Vertical contraction scour at bridges with water flowing under
pressure conditions. Transportation Research Record 1647 Paper No. 98-0443
2. Kimura I, Hosoda T, Onoda S (2002) Numerical simulator on full staggered boundary fitted
coordinate system for the analysis of 3D turbulent flows in open channels. Yokkaichi Univ J
Environ Inf 5(combined issue for no. 1 and 2):145–170 (in Japanese)
3. Meyer-Peter E, Müller R (1948) Formulas for bed-load transport. In: Proceedings of 2nd meeting,
IAHR, Stockholm Sweden, pp 39–64
4. Shields A (1936) Application of similarity principles and turbulence research to bed-load
movement. Report (trans: Ott WP, van Uchelen JC, California). Institute of Technology, Pasadena
5. Umbrell ER, Young GK, Stein SM, Jones JS (1998) Clear-water contraction scour under bridges
in pressure flow. J Hydraul Eng 124(2):236–240
S. A. Majid and S. Tripathi
Fig. 3 Scour hole geometry along the length of channel for a different lengths and b different
degrees of contraction
4 Conclusions
The present study is based on the numerical simulations of the pressure flow scouring
due to vertical contraction in a flow passage. The scouring thus induced is a function
of the flow geometry and bed characteristics. However, the present study is restricted
to the flow geometry only. Other parameters like bed slope, flow depth, particle
diameter and the flow velocity are kept constant. It is observed that the bed shear
has the maximum value inside the contraction. For all the simulations, the scour
hole is observed to develop within the contraction towards the upstream face of the
contraction. The magnitude of maximum scour is a function of both the length of
the contraction and the degree of the contraction. The magnitude of maximum scour
increases with increase in degree of contraction or length of contraction or both. A
complete understanding of the pressure flow scour would require the inclusion of
the other flow and bed properties in the simulations and the validation of numerical
results with experimental observations.
References
1. Arneson LA, Abt SR (1998) Vertical contraction scour at bridges with water flowing under
pressure conditions. Transportation Research Record 1647 Paper No. 98-0443
2. Kimura I, Hosoda T, Onoda S (2002) Numerical simulator on full staggered boundary fitted
coordinate system for the analysis of 3D turbulent flows in open channels. Yokkaichi Univ J
Environ Inf 5(combined issue for no. 1 and 2):145–170 (in Japanese)
3. Meyer-Peter E, Müller R (1948) Formulas for bed-load transport. In: Proceedings of 2nd meeting,
IAHR, Stockholm Sweden, pp 39–64
4. Shields A (1936) Application of similarity principles and turbulence research to bed-load
movement. Report (trans: Ott WP, van Uchelen JC, California). Institute of Technology, Pasadena
5. Umbrell ER, Young GK, Stein SM, Jones JS (1998) Clear-water contraction scour under bridges
in pressure flow. J Hydraul Eng 124(2):236–240