Hydraulic structures and Hydraulic design

Question 1

What are the hydraulic control structures for flow measurements, regulation and discharge?

Answer 1

Measurements = Thin-plate weir
Regulation = Long-based weir
Discharge = Overflow spillway.

Question 2

Difference between sluice flow gate and a weir flow?

Answer 2

Sluice flow is discontinuous and flow is affected by the gate.
Weir flow is continuous and flow is unaffected by the sluice gate.

Question 3

How to tell if flow is sluice or weir?

Answer 3

for flat structure:
e/H <= 0.65 - sluice flow
e/H >0.65 - weir

For curved structure
e/H <= 0.75 - sluice flow
e/H >0.75 - weir

e = sluice gate height
H= water head from top of structure.

Question 4

How to calculate discharge of weir flow?

How is it modified for submerged and contracted flow ?

Answer 4

Q = m*b*sqrt(2*g) *Ho^(3/2)
m = discharge coefficient 
m = k / sqrt(1 + E)

Submerged:
Q = sigmambsqrt(2g) *Ho^(3/2). (sigma < 1)

Contacted:
Q = Embsqrt(2g) *Ho^(3/2). (E< 1)

Question 5

What is the discharge coefficient for thin-plate weirs?

Rectangular or Triangular

Answer 5

Rectangular:
Mo = 0.403 + 0.053*H/P1 + 0.0007/H

Triangular:
Q = CH^5/2. C =1/4 for right angular

Question 6

Calculation for sluice flow?

Submerged?

Answer 6

Q = u*b*e*sqrt(2*g*Ho)
u = discharge coefficient

Q = ubesqrt(2g(Ho-h))
or
Q = sigmaubesqrt(2g*Ho)
(sigma < 1)