At steady state the temperature profiles in a laminated system appear thus. Which material has the higher thermal conductivity?
Compute the Prandtl number for He and H2O
a) by using the Eucken formula and experimental heat capacity data, at 1 atm and 300 K.
b) by using also the viscosity and the thermal conductivity of the relevant gases given below.
|
Gas
|
Cp x 10-3
|
m x 105
|
k
|
|
|
J/kg K
|
Pa s
|
W/m K
|
|
He
|
5.193
|
1.995
|
0.1546
|
|
H2O
|
1.864
|
1.041
|
0.02250
|