Flip Bucket Problem
Flip Bucket Problem
(OP)
Hello,
I am trying to figure out the horizontal distance that a water jets out off a steep channel. The channel ends at edge of a cliff. The objective is to determine the horizontal distance the flow will travel before it impacts the ground (which is 16' below).
Basically, the structure involves a steep (s=0.4) 2.5' width rectangular channel which ends in a 2' long horizontal section. A 5.5' radius is applied to the transition. Design flow is 10.6 cfs. I've attached a sketch.
Doing my research, it seems that the 2' long horizontal section may be too short to generate a hydraulic jump. Plus, a hydraulic jump is not desirable.
This may not fit a flip-bucket scenario since there is no bucket lip. (EM 1110-2-1603). The lip is not desirable because of standing water issue.
Is there any method out there that I can use to approximate a solution?
Appreciate the help.
Saurabh
I am trying to figure out the horizontal distance that a water jets out off a steep channel. The channel ends at edge of a cliff. The objective is to determine the horizontal distance the flow will travel before it impacts the ground (which is 16' below).
Basically, the structure involves a steep (s=0.4) 2.5' width rectangular channel which ends in a 2' long horizontal section. A 5.5' radius is applied to the transition. Design flow is 10.6 cfs. I've attached a sketch.
Doing my research, it seems that the 2' long horizontal section may be too short to generate a hydraulic jump. Plus, a hydraulic jump is not desirable.
This may not fit a flip-bucket scenario since there is no bucket lip. (EM 1110-2-1603). The lip is not desirable because of standing water issue.
Is there any method out there that I can use to approximate a solution?
Appreciate the help.
Saurabh





RE: Flip Bucket Problem
RE: Flip Bucket Problem
You can check the velocity lose and potential of a hydraulic jump over the 2' level section by iteratively solving a combination of Bernoulli's and Manning's:
d1 + V1^2/2g = d2 + V2^2/2g + L{Qn/[aAR^(2/3)]}^2
Then, check the froude at the downstream end:
F2 = V2/(gd)^0.5
(if Froude > 1, a hydraulic jump will occur)
AR^(2/3) solved using the average depth (d1+d2)/2
X = Vertical Drop
d = depth
V = Velocity
g = gravity 32.2 ft/sec/sec
L = legth of level section
Q = Flow
n = Manning's
A = Flow Area
R = Hydralic Radius
F = Froude
a = 1.49 (U.S.)