Kinetic Theory
 

hi

In the ideal gas model using the kinetic theory for Cp and K, which are the values to insert in degrees of freedom...........

thanks in advance payment

Re: Kinetic Theory
 

Hi,

the number of translational and rotational modes are added up. For monatomic gasses this is 3 for diatomic this is 5 ie 3 translations and 2 rotations.

Cv=DOF/2*R/M Cp=(DOF+2)/2*R/M

R=universal Gas Constant 8.314[kJ/kg/K] M=mollecular Weight [kg/kmol]

So let us try this for Argon, DOF=3, M=39.94[kg/kmol]

Plug it in and get 0.527[kJ/kg/K]

compare to Reynold's and Perkins, "Engineering Thermodynamics" talbe B-6b 0.523[kJ/kg/K]

Similarly k=Cp/Cv=3/5=1.67

Try it out for nitrogen and oxygen and you will get pretty good comparison as well, ie k=1.4! So as a first approximation it works quite well for monatomic and diatomic gasses.

Regards,

BAK_FLOW