Chapter 3: Properties of Thermodynamic Media

Example 3.1, page no. 43

In [1]:
#initilisation
P = 80                        #lb/in^2
x = 0.9                       #quality
hg = 1183.1                   #B/lbm
hfg = 901.1                   #B/lbm

#calculation
h=hg-(1-x)*hfg

#result
print "Enthalpy of steam = ", round(h), "B/lbm"

Enthalpy of steam =  1093.0 B/lbm

Example 3.2, page no. 44

In [3]:
#initilisation
P = 100                         #lb/in^2
T = 470                         #F
T2 = 500                        #F
T1 = 450                        #F

#calculation
#From table 4 of appendix
v1 = 5.268
v2 = 5.589
v = v1+2*(v2-v1)/5.0

#result
print "Specific volume at ", T, "F", "= ", round(v,3), "ft**3/lbm"

Specific volume at  470 F =  5.396 ft**3/lbm

Example 3.3, page no. 47

In [5]:
#initilisation

R = 1544.0                    #ft-lb/R
M = 44.0                      #lbm

#calculation
Rdash=R/M

#result
print "Gas constant for CO2 = ", round(Rdash, 1), "ft-lb/lbm R"

Gas constant for CO2 =  35.1 ft-lb/lbm R

Example 3.4, page no. 48

In [1]:
#initialisation
h = 138.7                  #enthalpy - from table 6
t = 580.0                  #R absolute temprature
p = 11520.0                #pressure
g = 53.3                   #gas constant

#calculation
#v = RT/P

v = (g*t)/p

#result
print "The volume for air at given conditions is ", round(v, 2), "ft**3/lbm"

The volume for air at given conditions is  2.68 ft**3/lbm