Posted by(작성하신 분) rex ( August 24, 2000 at 11:07:54: )
In Reply to(원문) : Restriction pressure loss in tubes
posted by(원문 작성자) : W. Arthur Fisher on August 15, 2000 at 13:58:55:
Use Bernoulli's Principle.
It means where the velocity of a fluid is high,
the pressure becomes low,
and where the velocity is low,
the pressure becomes high.
For the steady flow of an ideal fluid
P1 + 1/2(density)v1^2 =P2 + 1/2(density)v2^2
thus in your case
P1=35 bar, 12 cubic m/h => v1=6.79 m/s (ID=25 mm)
P2=> should become 25 bar at downstream point 2
density= 1000 kg/cb.m (water)
so the reducer ID should be 10 mm (9.7 mm)
in order to get 25 Bar downstream
the velocity at downstream (point 2)
should be 45.2 m/s, this requires the ID at 2
should be 9.7 mm
Thus in frictionless case, if you reduce the ID
from 25 mm to 9.7 mm, the pressure will decrease
to 25 bar(2500000 Pa).
rex