Scientific American Supplement, No. 470, January 3, 1885 — John Shaqi
Scientific American Supplement, No. 470, January 3, 1885Various
Science
Scientific American Supplement, No. 470, January 3, 1885
Various
Science -- Periodicals
At a recent meeting in this city of the American Society of Civil
Engineers, a paper by Edmund B. Weston was read, giving the description
and result of experiments on the flow of water through a 2½ inch hose and
through nozzles of various forms and sizes; also giving the results of
experiments as to the height of jets of water. The experiments were made
at Providence, R.I. The water was taken from a hydrant to the head of
which were attached couplings holding two pressure gauges, and from the
couplings the hose extended to a tank holding 2,100 gallons, so arranged
as to measure accurately the time and amount of delivery of water by the
hose. Different lengths of hose were used. The experiments resulted in the
following formula for flow from coupling:
1. For hose between 90 and 100 feet in length, and where great accuracy is
required:
---------------------------------------------------
/ 2gh
V = / ---------------------------------------------------
/ / 0.504 \
\/ 1 - 0.0256d^{4} + ( 0.0087 + ------- ) 0.12288d^{4}l.
\ --- /
\/ v
[TEX: V = \sqrt{\frac{2gh}{1 - 0.0256 d^4 + (0.0087 +
\frac{0.504}{\sqrt{v}}) 0.12288 d^4 l}}.]
2. For all lengths of hose, a reliable general formula:
----------------------------------------------
/ h
V = / ----------------------------------------------
\/ 0.0155463 - 0.000398d^{4} + 0.0000362962d^{4}l.
[TEX: V = \sqrt{\frac{h}{0.0155463 - 0.000398 d^4 + 0.0000362962 d^4 l}}.]
g being velocity of efflux in feet per second.
h, head in feet indicated by gauge.
d, of coupling in inches.
l, length of hose in feet from gauge.
v, velocity in 2½ inch hose.
Forty-five experiments were made on ring nozzles, resulting in the
following formula:
f = 0.001135v².
f being loss of head in feet owing to resistance of nozzle, and v the
velocity of the contracted vein in feet per second.
Thirty-five experiments were made with smooth nozzles, resulting in the
following formula:
f = 0.0009639 v².
f being the loss of head in feet owing to resistance, and v the
velocity of efflux in feet per second.
Experiments show that a prevailing opinion is incorrect that jets will
rise higher from ring nozzles than from smooth nozzles.
Box's formula for height of jets of water compares very favorably with
experimental results.
* * * * *
IRON PILE PLANKS IN THE CONSTRUCTION OF FOUNDATIONS UNDER WATER.
Public-domain text, read in full here on John Shaqi.
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