Intro

This library implements advanced derivative techniques to allow for implementation of EOS without any hand-written derivatives. The name TEQP comes from Templated Equation of State Package

So far the following EOS are implemented:

• van der Waals
• Peng-Robinson
• Soave-Redlich-Kwong
• PC-SAFT
• cubic plus association (CPA) for pure fluids
• multi-fluid model in the form of GERG

Written by Ian Bell, NIST.

Changelog

• 0.7.0 Significant changes include:

  • get_Arxy generalized to allow for any derivative

  • Local stability tests for critical points can be enabled

  • Critical curve polishers much more reliable

  • Add a method for dp/dT along isopleth of phase envelope of mixture.

  • Estimation is not enabled by default by the estimation flag. If that is desired, use force-estimation

• 0.6.0 Add VLLE from VLE routine based upon https://pubs.acs.org/doi/abs/10.1021/acs.iecr.1c04703

• 0.5.0 Add VLE polishing routine (https://github.com/usnistgov/teqp/commit/50b61af05697c01c0a2bf686b256724cc79f73d4), fix bug in critical curve tracing misalignment of eigenvectors(https://github.com/usnistgov/teqp/commit/f01ac7be43fcca4e1cd3c502be0259755396436b), assorted issue fixes, especially support for javascript

• 0.4.0 Add VLE tracing, code coverage and valgrind testing, fugacity_coefficients, generalize loading of multifluid models

• 0.3.0 Add integration options to the tracing of the critical curve; fix __version__

• 0.2.0 Add fluid files to the python package

Install

For windows and OSX, you should be able to install the most recent version from PYPI with

pip install teqp

For linux users, please build yourself following the instructions below.

The windows wheels are built/pushed with the buildwheels.py script, the OSX wheels are built as part of github action

Tests

Build (cmake based)

Try it in your browser:

Be aware: compiling takes a while in release mode (multiple minutes per file in some cases) thanks to the use of generic typing in the models. Working on making this faster...

For example to build the critical line tracing example in visual studio, do:

mkdir build
cd build
cmake .. 
cmake --build . --target multifluid_crit --config Release
Release\multifluid_crit

On linux/OSX, similar:

mkdir build
cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --target multifluid_crit
./multifluid_crit

Random notes for future readers:

• When building in WSL via VS Code, you might need to enable metadata to avoid pages of configure errors in cmake: https://github.com/microsoft/WSL/issues/4257
• Debugging in WSL via VS Code (it really works!): https://code.visualstudio.com/docs/cpp/config-wsl