Experimental Evaluation of Hydraulic Performance of Outlet Structures with Baffle Blocks under Super critical Flows
The design of outlet transition in field irrigation system requires the flow attaining a uniform velocity at the end of such structures. In addition, super critical flow condition requires maximizing the dissipation of hydraulic energy possessed by the flowing water to hold its erosion capacity to...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English English |
| Published: |
Universiti Putra Malaysia Press
2001
|
| Online Access: | http://psasir.upm.edu.my/id/eprint/3633/1/Fatigue_Modelling_for_Stone_Mastic_Asphalt_%28SMA%29.pdf http://psasir.upm.edu.my/id/eprint/3633/ |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The design of outlet transition in field irrigation system requires the flow attaining a uniform velocity at the end of such structures. In addition, super critical flow condition requires maximizing the dissipation of hydraulic energy possessed by the flowing water
to hold its erosion capacity to a minimum. Floor baffle blocks incorporated in the outlet
transition are useful for the above objectives. This laboratory investigation attempts to
evaluate the effects of the relative sizes and arrangements of different types of baffle
blocks on hydraulic performances of outlet transition of different configurations operating
at super critical flow conditions. Dimensional analysis techniques were used to develop dimensionless ratios describing the geometry and the flow within an outlet transition containing certain types of
appurtenance structures. The solution was evaluated in the laboratory with respect to
measurable elements of the flow to achieve standardization and general evaluation of the
effectiveness of the different types of baffle blocks. The results are presented in the form
of dimensionless plots, which show the variation of the ratios developed earlier, with the
controlled variation of Froude numbers.
Expanding channel outlet transitions of straight-wall type of angle 10 0 , 20 0 and 30
o with two expansion ratios of 4 and 6 were tested with and without floor baffles. The
outlets with baffles are generally found to be effective in creating optimum flow
conditions than the plain outlets. The use of baffles also resulted in higher dissipation
of energy within the outlets, with baffles having curved upstream edge (in plan)
dissipated up to 42.7% more energy than the plain outlets. |
|---|