Chapter 11: GETTING STARTED IN FLUID MECHANICS: FLUID STATICS

Example 11.01, page: 253

In [2]:
from __future__ import division
import math

# Initialization  of  Variable
rgas = 42.5 #lbf/ft3
rwater = 62.4 #lbf/ft3
hgas = 17 #ft
hwater = 3 #ft

#calculations:
#pressure relative to atmospheric pressure at 1
#Pdiff1 = P1- P0
Pdiff1 = rgas*hgas
#corresponding pressure head in feet of water is therefore at 1
#head1 = (P1-P0)/rwater
head1 = Pdiff1/rwater
#pressure relative to atmospheric pressure at 2(bottom)
#Pdiff2 = P2- P0
Pdiff2 = rwater*hwater + Pdiff1
#corresponding pressure head in feet of water is therefore at 1
#head2 = (P2-P0)/rwater
head2 = Pdiff2/rwater

#Results
print " the pressure relative to atmospheric pressure at junction is", Pdiff1,"lbf/ft2 or", round(Pdiff1/144,2),"lbf/in2"
print " corresponding pressure head in feet of water is", round(head1,1),"ft"
print " the pressure relative to atmospheric pressure battom is", Pdiff2,"lbf/ft2 or", round(Pdiff2/144,2),"lbf/in2"
print " corresponding pressure head in feet of water is", round(head2,1),"ft"

 the pressure relative to atmospheric pressure at junction is 722.5 lbf/ft2 or 5.02 lbf/in2
 corresponding pressure head in feet of water is 11.6 ft
 the pressure relative to atmospheric pressure battom is 909.7 lbf/ft2 or 6.32 lbf/in2
 corresponding pressure head in feet of water is 14.6 ft

Example 11.02, page: 258

In [3]:
from __future__ import division
import math

# Initialization  of  Variable
SGoil = 0.9
rwater = 62.4 #lbf/ft3
h1 = 36/12 #ft
h2 = 6/12 #ft
SGhg = 13.6
h3 = 9/12 #ft

#calculations:
Pair = -1*SGoil*rwater*(h1 + h2) + SGhg*rwater*h3
#gage pressure
Pgage = Pair/144

#Results
print  "Gage  pressure is",round(Pgage,2),"lbf/in2(psi)" 

Gage  pressure is 3.06 lbf/in2(psi)

Example 11.03, page: 262

In [4]:
from __future__ import division
import math

# Initialization  of  Variable
b = 2 #m
r = 9.8E3 #N/m3
a = 4 #m

#calculations:
Yc = 8
#area
A = b*a
hc = Yc*math.sin(60*math.pi/180)
FR = r*hc*A
#moment of Inertia
Ixc = (b*a**3)/12
#location
YR = Ixc/(Yc*A) + Yc

#Results
print  "the magnitude and location of the resultant force exerted on the gate by the water are", round(FR,0),"N at", round(YR,2),"m" 

the magnitude and location of the resultant force exerted on the gate by the water are 543171.0 N at 8.17 m