The ThermoPack C++ wrapper is a header-only wrapper designed to be compatible with stl containers like std::vector, and to support use of std::unique_ptr and cousins. In short, it is intended to make using ThermoPack together with modern C++ as painless as possible.

• Building ThermoPack
• ThermoPack headers
• Including and linking ThermoPack
• Library structure
• Examples

Building ThermoPack

The ThermoPack C++ wrapper is a header-only wrapper, that simplifies linking to the libthermopack library that is built and installed with the CMakeLists.txt in the root directory of ThermoPack.

To build the required library,

git clone https://github.com/thermotools/thermopack.git
cd thermopack
mkdir build
cd build
cmake ..
make install

This should generate the file thermopack/addon/cppThermopack/libthermopack.[so/dylib], which you will later be linking to.

ThermoPack headers

The header files you will need are found in thermopack/addon/cppThermoPack/cppThermoPack.

Including and linking ThermoPack

An example CMakeLists.txt is found in thermopack/addon/cppExamples. In essence, all that is required to include ThermoPack is to add the following to your CMakeLists.txt:

set(THERMOPACK_HEADERS "path/to/thermopack/addon/cppThermopack")
set(libthermopack_path "path/to/thermopack/addon/cppThermopack/libthermopack.[so/dylib]")

target_link_libraries(<my_project> ${libthermopack_path})
target_include_directories(<my_project> ${THERMOPACK_HEADERS})

where <my_project> is some target previously defined by a call to add_executable, add_library, etc.

Library structure

The ThermoPack C++ wrapper defines a class structure that is almost identical to the structure in the python wrapper. All equations of state inherit from the Thermo class (defined in thermo.h), and only implement initialization and some minor utility methods.

In addition, several utility structures are defined in utils.h. These include the Property and VectorProperty classes, which are used to hold computed values and derivatives. The structures support implicit conversion to respectively double and std::vector<double>, such that their existence can be ignored unless you are interested in computing derivatives.

The result of phase equilibrium calculations, such as flash- and saturation point calculations, are returned as a FlashResult object, which holds the attributes

• double T - Temperature (K)
• double p - Pressure (Pa)
• double betaV - Vapour fraction
• double betaL - Liquid fraction
• std::vector<double> z - Total composition
• std::vector<double> x - Liquid composition
• std::vector<double> y - Vapour composition
• std::string flash_type - Information about the calculation this object originated from

Examples

Some sample programs using ThermoPack in C++ are found in the directory thermopack/addon/cppExamples. To build them, navigate to that directory, and

mkdir build
cd build
cmake ..
make

This will build the examples as executables in the build directory.

Currently implemented examples are

• basic - Demonstrates initialization of some equations of state
• flashes - Flash calculations
• tp_properties - Compute properties at given temperature and pressure
• tv_properties - Compute properties at given temperature and volume
• saturation - Compute dew- and bubble points, and the critical point of a mixture