1)water flows down a pipe which tapers from 150mm diameter to 100mm
diameter at the lower end.the difference in height between the two ends of the
pipe is 3.0m and the rate of flow is 0.8m^3/min.calcuate the pressure differece
between the upper and lower ends of the pipe .given density of the water is
1000kg/m^3.
2)a horizontal pipe carries water tapers from 80mm diameter to 50mm diameter.
the pressure at the wider end is 100kpa and the other end is 70kpa.calculate the
velocity of the water at each end of the pipe and the volume passing through the pipe per second. given density of the water is 1000kg/m^3.
物理 fluid mechanics
2009-10-20 1:25 am
回答 (3)
2009-10-20 6:05 am
✔ 最佳答案
1. Assume water is imcompressible, the rate of flow at any point should be the same.The rate flow = 0.8 / 60 = 0.0133 m^3/s
The velocity of the water flow in the upper end, v1 = 0.0133 / pi(0.075)^2 = 0.755 m/s
The velocity of the water flow in the lower end, v2 = 0.0133 / pi(0.05)^2 = 1.693 m/s
By Bernoulli's Principle,
P1 + 1/2 pv1^2 + pgh1 = P2 + 1/2 pv2^2 + pgh2
Pressure difference, P1 - P2 = (1/2 pv2^2 - 1/2 pv1^2) + (pgh2 - pgh1)
= 1/2 (1000)(1.693^2 - 0.755^2) + (1000)(10)(-3)
= -2.89 X 10^4 Pa
With the upper end be at a lower pressure.
2. There isn't enough information to calculate.
參考: Physics king
2009-10-21 8:00 am
2009-10-20 11:32 pm
The velocity of the water flow in the upper end, v1 = 0.0133 / pi(0.075)^2 = 0.755 m/s
The velocity of the water flow in the lower end, v2 = 0.0133 / pi(0.05)^2 = 1.693 m/s
pi(0.075)^2 and pi(0.05)^2 是怎樣出來???
The velocity of the water flow in the lower end, v2 = 0.0133 / pi(0.05)^2 = 1.693 m/s
pi(0.075)^2 and pi(0.05)^2 是怎樣出來???
收錄日期: 2021-04-19 15:59:09
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