Hydraulic Structures: Fourth Edition

CdCc

 1 Cc

H

a



1/2

. (6.4)

For a vertical gate the coefficient of contraction Ccvaries slightly between
0.6 and 0.61 (Henderson, 1966) with free flow conditions generally
fory 3 /y 1 0.5 (see Figs 6.9 and 6.10). For non-modular flow the condi-
tions indicated in Fig. 6.9 apply; equation (6.3) may still be used but the

HYDRODYNAMIC FORCES ACTING ON GATES 281

2

y

3

a

1

p y 1

rg

y 2

y 3

Fig. 6.9 Flow under a vertical gate

Cd

0.6

0

0 16

0.5

0.4

0.3

0.2

0.1

2

2 3

4

4 5

6

6 7

8

8

(^10) y 1 12 14
a
y 3
a
Free discharge
Fig. 6.10 Cd
y
a
1
,
y
a
3