244
Molesworth’s pocket-book
Discharge of Water fbom Orifices, Sluices, &c.
V = Theoretical velocity due to the head oi
water (from surface of water to centre
of orifice). See next page.
A = Area of aperture in square feet.
Q = Quantity discharged in cubic feet *
K — Coefficient for different orifices.
E = Velocity of efflux.
e = vk. q=ea
Values of Kfor Different Orifices.
For vena contracta, orifice at) v „„
cistern .. _.................. y K=:’97
Converging mouthpiece, angle j
13|S nai row end .. ., i
Diverging 5“ ) Narrow end ..
I Broad end ..
= •91
•92
55
[ (Cylindrical, bore i to 1 length =-81
F" 1 J >■ » i to-jl- „ =-77
J I " » iVt«>Ä » =‘73
" A A » = • 6?
""‘Tl Short tube projecting inwards.. = • 68
J Orifice in a thin plate .. — »gi,
• , , ±,Forwide oprings whose bottom 1
is on a level with that of the reservoir; for sluices I
with walls in a line with the orifices; for bridges ?=-96
with pointed piers............................... J
Fur narrow openings whose bottom is on å line with (
that of the reservoir; for abrupt projections and I =• 86
square piers of bridges............. .. .. . )
ror sluices without side waili., f --■qz