Evolution of Developing Flushing Cone during the Pressurized Flushing in Reservoir Storage
Sedimentation in reservoirs and the corresponding
loss of storage capacity is one of the most serious problems in dam
engineering. Pressurized flushing, a way to remove sediments from the reservoir, is flushing under a pressurized flow condition and
nearly constant water level. Pressurized flushing has only local
effects around the outlet. Sediment in the vicinity of the outlet openings is scoured and a funnel shaped crater is created. In this study, the temporal development of flushing cone under various
hydraulic conditions was studied experimentally. Time variations of
parameters such as maximum length and width of flushing and also
depth of scouring cone was measured. Results indicated that an
increase in flow velocity (and consequently in Froude number)
established new hydraulically conditions for flushing mechanism and
so a sudden growth was observed in the amount of sediment released
and also scouring dimenssions. In addition, a set of nondimensional
relationships were identified for temporal variations of flushing scour
dimenssions, which can eventuallt be used to estimate the development of flushing cone.
[1] Olesen, K.W., Basson, G. (2004) "A 2D model for reservoir sedimentation and flushing", Conference of Hydraulics of Dams in Iran.
[2] Shen, H.W. and Lai J.-S. 1996. "Sustain reservoir useful life by flushing
sediment". International Journal of Sediment Research. Vol. 11(3): 10-
17.
[3] Brandt, S. A. 2000. "A review of reservoir desiltation". International
Journal of Sediment Research. Vol. 15, No. 2. pp. 321-342.
[4] Brown, C.B. 1943. "The Control of Reservoir Silting". United States
Department of Agriculture, Miscellaneous Publication No. 521,
Washington, D.C. p. 166.
[5] Qian, N. 1982. " Reservoir sedimentation and slope stability; technical
and environmental effects". Fourteenth International Congress on Large
Dams, Transactions, Rio de Janeiro, Brazil, 3-7 May, Vol. III. pp. 639-90.
[6] White W.R. and Bettess R. 1984, "The feasibility of flushing sediments
through reservoirs". Challenges in African Hydrology and Water
Resources, Proceeding of Harare Symposium, July, D.E. Walling, S.S.D.
Foster, P. wurzel, eds, IAHS Publication No.
[7] Fang D. and Cao S. 1996 An experimental study on scour funnel in front
of a sediment flushing outlet of a reservoir. Proceedings of the 6th
Federal Interagency SedimentationConference.
[8] Shen H.W., Lai J.S. and Zhao D. 1993, "Hydraulic desiltation for
noncohesive sediment". Proceeding of the 1993 Annual ASCE
Hydraulic Engineering Conference, San Francisco, H.W Shen, S.T. Su,
and F. Wen, eds, pp. 119-124.
[9] Scheuerlein, H., Tritthart M and Nunez Gonzalez F. 2004. "Numerical
and physical modeling concerning the removal of sediment deposits
from reservoirs". Conference proceeding of Hydraulic of Dams and
River Structures, Tehran, Iran.
[10] Emamgholizadeh, S., Samadi H. and Bina M. 2005. "The flushing of the
sediment near the powerintakes in the Dez Reservoir". River Basin
Management. Italy.
[11] Emamgholizadeh, S., Bina M. Fathimoghadam M. and GHomeyshi M.
2006. "Investigation and Evaluation of the Pressure Flushing Through
Storage Reservoir", ARPN Journal of Engineering and Applied Sciences. Vol. 1, No. 4.
[1] Olesen, K.W., Basson, G. (2004) "A 2D model for reservoir sedimentation and flushing", Conference of Hydraulics of Dams in Iran.
[2] Shen, H.W. and Lai J.-S. 1996. "Sustain reservoir useful life by flushing
sediment". International Journal of Sediment Research. Vol. 11(3): 10-
17.
[3] Brandt, S. A. 2000. "A review of reservoir desiltation". International
Journal of Sediment Research. Vol. 15, No. 2. pp. 321-342.
[4] Brown, C.B. 1943. "The Control of Reservoir Silting". United States
Department of Agriculture, Miscellaneous Publication No. 521,
Washington, D.C. p. 166.
[5] Qian, N. 1982. " Reservoir sedimentation and slope stability; technical
and environmental effects". Fourteenth International Congress on Large
Dams, Transactions, Rio de Janeiro, Brazil, 3-7 May, Vol. III. pp. 639-90.
[6] White W.R. and Bettess R. 1984, "The feasibility of flushing sediments
through reservoirs". Challenges in African Hydrology and Water
Resources, Proceeding of Harare Symposium, July, D.E. Walling, S.S.D.
Foster, P. wurzel, eds, IAHS Publication No.
[7] Fang D. and Cao S. 1996 An experimental study on scour funnel in front
of a sediment flushing outlet of a reservoir. Proceedings of the 6th
Federal Interagency SedimentationConference.
[8] Shen H.W., Lai J.S. and Zhao D. 1993, "Hydraulic desiltation for
noncohesive sediment". Proceeding of the 1993 Annual ASCE
Hydraulic Engineering Conference, San Francisco, H.W Shen, S.T. Su,
and F. Wen, eds, pp. 119-124.
[9] Scheuerlein, H., Tritthart M and Nunez Gonzalez F. 2004. "Numerical
and physical modeling concerning the removal of sediment deposits
from reservoirs". Conference proceeding of Hydraulic of Dams and
River Structures, Tehran, Iran.
[10] Emamgholizadeh, S., Samadi H. and Bina M. 2005. "The flushing of the
sediment near the powerintakes in the Dez Reservoir". River Basin
Management. Italy.
[11] Emamgholizadeh, S., Bina M. Fathimoghadam M. and GHomeyshi M.
2006. "Investigation and Evaluation of the Pressure Flushing Through
Storage Reservoir", ARPN Journal of Engineering and Applied Sciences. Vol. 1, No. 4.
@article{"International Journal of Earth, Energy and Environmental Sciences:52072", author = "Meshkati M. E. and Dehghani A. A. and Naser G. and E mamgholizadeh S. and Mosaedi A.", title = "Evolution of Developing Flushing Cone during the Pressurized Flushing in Reservoir Storage", abstract = "Sedimentation in reservoirs and the corresponding
loss of storage capacity is one of the most serious problems in dam
engineering. Pressurized flushing, a way to remove sediments from the reservoir, is flushing under a pressurized flow condition and
nearly constant water level. Pressurized flushing has only local
effects around the outlet. Sediment in the vicinity of the outlet openings is scoured and a funnel shaped crater is created. In this study, the temporal development of flushing cone under various
hydraulic conditions was studied experimentally. Time variations of
parameters such as maximum length and width of flushing and also
depth of scouring cone was measured. Results indicated that an
increase in flow velocity (and consequently in Froude number)
established new hydraulically conditions for flushing mechanism and
so a sudden growth was observed in the amount of sediment released
and also scouring dimenssions. In addition, a set of nondimensional
relationships were identified for temporal variations of flushing scour
dimenssions, which can eventuallt be used to estimate the development of flushing cone.", keywords = "Pressure Flushing, Dam, Sediment, Scouring.", volume = "3", number = "10", pages = "321-5", }