To find the quantity of Water that will be discharged through an orifice, or pipe, in the side or bottom of a Vessel.

Area of orifice, sq. in. X

No. corresponding to height of surface above orifice, as per table

= Cubic feet discharged per minute.

Height of

Surface above

Orifice.

Multiplier.

Ft.

1

2.25

2

3.2

4

4.5

6

544

8

64

10

7 1

12

7.8

14

84

16

9.

Height of

Surface above

Orifice.

Multiplier.

Ft.

18

9.5

20

10.

22

10.5

24

11.

26

11.5

28

12.

30

12.3

32

12 7

35

13.3

Height of

Surface above

Orifice.

Multiplier.

Ft.

40

14.2

45

15.1

50

16.

60

17.4

70

18.8

80

20.1

90

21.3

100

22.5

To find the size of hole necessary to discharge a given quantity of Water under a given head.

Cubic ft. water discharged / No. corresponding to height, as per table = Area of orifice, sq. in.

To find the height necessary to discharge a given quantity through a given orifice.

Cubic ft. water discharged / Area orifice, sq. inches. = No. corresp. to height, as per table.

The velocity of Water issuing from an orifice in the side or bottom of a vessel being ascertained to be as follows;

√Height ft. surface above orifice X 5.4 =

Velocity of water, ft. per second.

√Height ft. X Area orifice, ft. X 324 =

Cubic ft. discharged per minute.

√Height ft. X Area orifice, ins. X 2.2 = Do. Do.

It may be observed, that the above rules represent the actual quantities that will be delivered through a hole cut in the plate; if a short pipe be attached, the quantity will be increased, the greatest delivery with a straight pipe being attained with a length equal to 4 diameters, and being 1-3 more than the delivery through the plain hole; the quantity gradually decreasing as the length of pipe is increased, till, with a length equal to 60 diameters the discharge again equals the discharge through the plain orifice. If a taper pipe be attached the delivery will be still greater, being 1 times the delivery through the plain orifice; and it is probable that if a pipe with curved decreasing taper were to be tried, the delivery through it would be equal to the theoretical discharge, which is about 1.65 the actual discharge through a plain hole.

To find the quantity of Water that will run through any orifice, the top of which is level with the surface of water as over a sluice or dam.

√Height, ft. from water surface to bot-tom of orifice or top of dam

X

Area of water passage, sq. ft.

= Cub. ft. discharged per minute. Or,

Two-thirds Area of water passage, sq. ins X No. corresponding to height as per table, = Cub. ft. discharged per minute.

To find the time in which a Vessel will empty itself through a given orifice.

√Height ft. surface above orifice x Area water surface, sq, ins. /Area orifice, sq. in. X 3.7

= Time required, seconds.

The above rules are founded on Bank's experiments.