Solve Non-linear System - EOS Critical Conditions

[mnori]

Dear All,

I would like to receive clarifications about the solution of a nonlinear system through the use of a solve block Given/Find. In the attachment it is reported the  system that make use of the symbolic derivative operators ( EOS isothermal inflection point- critical conditions ) . The solution converges only up to a certain value of the input parameter ( epsaa, Vaa ).  Any suggestion how to solve this issue?

Your sincerely,

Massimiliano

[LucMeekes]

You're trying to solve the system for T=Tc. See what that does to the value of the Covolume Soft-core parameter:

You may get a division by zero.

Further:

I tried to solve the set symbolically (with part of the parameters defined)

and after 30 minutes it found no answer.

Hope this helps.

Success!
Luc

[mnori]

Hello Luc,

The system has three unknowns ( εc,η  and bc ) in three equations. As shown in attachment, the Solve Block is solved only up to a certain value of εaa and Vaa ( EOS parameters ).
  The equation you considered added a further variable : b.