Real gas pseudo-pressure calculation

[vinomarky]

It looks to be correct. Perhaps the problem is that you are doing the integration too coarsely?

If you fit a 5th order polynomial to viscosity, and 3rd order to Z as functions of P, then calculate the respective values at single psi increments and sum appropriately I get values that are pretty close - if you did the same via mathematical integration of the polynomials you'd probably get bang on.

Even if you use the data as given, you'd get in the ballpark

[pet_spec]

It looks to be correct. Perhaps the problem is that you are doing the integration too coarsely?

If you fit a 5th order polynomial to viscosity, and 3rd order to Z as functions of P, then calculate the respective values at single psi increments and sum appropriately I get values that are pretty close - if you did the same via mathematical integration of the polynomials you'd probably get bang on.

Even if you use the data as given, you'd get in the ballpark

Can you please show your method on paper and attach its scanned version? How do you make polynomial fitting?

Thanks