Canales

Specific Energy
Example
A Trapezoidal channel having: Bo = 6 m y = 1.8 m z=2 determine the R, D, E

Source: Chaudhry, 2008

Facultad de Ingeniería – Ingeniería Civil
IGC-020 HIDRÁULICASpecific Energy
Example
Bo = 6 m y = 1.8 m z=2
R A P
Source: Chaudhry, 2008

A by zy 2 17,28 m2

P b 2 y (1 z 2 ) 14 m2
R 1,23 m

E

y

v2 2g

Para un Q= 15 m3/s
v Q A 0,87 m 3 / s OkD

A T

T

b 2 zy 13,2 m D 1,31 m

E 1,83 m

Facultad de Ingeniería – Ingeniería Civil
IGC-020 HIDRÁULICA

Specific Energy
Example
A 4-m wide rectangular channel is carrying 10 m3/sat a depth of 2.5 m. There is a step rise of 0.2 m in the channel bottom. Assuming there are no losses at the transition, determine the flow depth downstream of the bottom step. Does the water surfacerise or fall at the step?

Source: Chaudhry, 2008

Facultad de Ingeniería – Ingeniería Civil
IGC-020 HIDRÁULICA

Specific Energy
Example
A 4-m wide rectangular channel is carrying 10 m3/sat a depth of 2.5 m. There is a step rise of 0.2 m in the channel bottom. Assuming there are no losses at the transition, determine the flow depth downstream of the bottom step. Does the water surfacerise or fall at the step? Given: Q = 10 m3/s B=4m y1 = 2.5 m Δz = 0.2 m No head losses at the transition Determine: y2 = ? Change in water-surface level = ?
Source: Chaudhry, 2008

Facultad deIngeniería – Ingeniería Civil
IGC-020 HIDRÁULICA

Specific Energy
Example

E1

E2

z
Facultad de Ingeniería – Ingeniería Civil
IGC-020 HIDRÁULICA

Specific Energy
Example
V1 Q2 2 g (by)2 y1 y2 v1 2g v2 2g
2 2

0,05 m / s

E1 E2

2,55 m

Reemplazando:

E1

E2
y2
3

z
2,35 y 2
2

2,35 m
0,32 0

y2

0,32 y2
2

y2

2,29 m

R/: 2,29 m + 0,2 m = 2,48 mDisminuye

Flujo crítico

MSc Maria alejandra caicedo l
IGC-020 Hidráulica de Canales

Flujo crítico

IGC-020 Hidráulica de Canales

Supuestos:
a)

Q

Cte

E

f ( y) Otra forma...