Is there a good heuristic to set the volume interval to calculate pressure along an isotherm? I mean I would like to have a plot that will cover the sub-cooled liquid- two phase region - and super-heated vapor region with good presentation rather than trying to fix the axis limit manually.
The other question is that when using cubic equations of state the pressure inside the two phase region may go below zero. Is there a way to avoid this negative pressure?
I have created countless such figures. While these curves are for steam, I have a lot of others for refrigerants and other fluids. You can see a variety of figures by just clicking on "Look Inside" without getting the book. Check out Azeotropes for the refrigerants and Thermodynamic and Transport Properties of Fluids too. All the software is free online. https://www.amazon.com/dp/B086P7G9CW
Take log steps on both sides of the vapor dome for subcritical and both sides of the critical density for supercritical isotherms like the following. It's the same as rho*=1.01, which you could easily do in an Excel spreadsheet.
void SubcriticalIsotherm(double T)
for(i=0;i
Excellent answer from Professor Dudley J Benton . I agree with him and recommend his response.
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