Flow pattern upstream of a constriction in an erodible channel

Document Type : Research Article



In the present paper flow pattern at a constriction in an open channel is studied experimentally. A constriction as a model of bridge site is constructed in a flume 73.5 cm wide and with erodible bed. Measurements were carried out after the scour hole was reached to its equilibrium condition. Tests were conducted with one flow discharge and two tail waters. Flow velocity was measured in 3 directions simultaneously with an ADV. Based on instantaneous velocities, turbulence intensity was also calculated and analyzed. The effect of constriction on flow pattern was then studied based on velocity and turbulence measurements in x, y and z directions. 


Richardson E V, Harrison L J, Richardson J R, Davies S R 1993 "Evaluating scour at bridges." Publ.
FHWA-IP-90-017, Federal Highway Administration, US Department of Transportation,Washington, DC.
Raudkivi,A.J.,1990”Loose­Boundary ydraulics”,Pergamon Press,Oxford
Kwan T F, Melville B W 1994 "Local scour and flow measurements at bridge abutments. "
J. Hydraul.Res. 32: 661–673.
S.Dey and A.K.Barbhuiya , December 2005 “ Flow Field at a Vertcal-Wall Abutment” Journal  of Hydraulic Engineering,pp.1126-1135.
S.Dey and A.K.Barbhuiya ,2006 “ 3D flow field in a scour hole at a wing-wall abutment” Journal  of Hydraulic Research, Vol.44,No.1, pp. 33-50.
Molinas ,A. and Marcus,K.B.” Chocking  in Water Supply Structures and Open Channels”. Journal of Hydraulics Research,Vol.36(4),1998,pp675-694.