In [1]:

```
# Variables
D = 0.0752; # Outer diameter in ft
T1 = 61.4; # Pipe surface temperature in degF
T2 = 69.9; # Air temperature in degF
Tf = (T1+T2)/2; # Film temperature at whih physical properties is to be measured
delT = T1-T2;
rho = 1.94; # Density in slug/ft**3 , 62.3/32.2
u = 0.0780; # vismath.cosity in slug/ft-hr , 2.51/32.2
Cp = 1*32.2; # heat capacity in Btu/slug-ft
k = 0.340; # thermal conductivity in Btu/hr-ft-degF
v = 7*3600; # velocity in ft/sec
# Calculations
Nre = D*v*rho/u; # Reynolds number
Npr = u*Cp/k; # Prandtls number
Nnu = 0.023*Nre**.8*Npr**.4;
h = Nnu*k/D; # heat transfer coefficient
# Results
print "The average film coefficient of heat transfer is %.d Btu/hr-ft**2-degF"%(h);
```

In [2]:

```
# Variables
D = 1./12; # Inner diameter of pipe in ft
k = 0.0174; # Thermal conductivity in btu/hr-ft-degF
Nre = 8000.; # Reynolds number
# Calculations
# From table we can find out nusselt number
Nnu = 0.3*Nre**0.57; # Nusselt number
h = round(Nnu)*k/D; # Heat transfer coefficient in btu/hr-ft**2-degF
# Results
print "heat transfer coefficient for air flowing is %.1f Btu/hr-ft**2-degF"%(h);
```