For instructions on building the KineticGas C++ library, see the installation guide.

A basic example showing initialization of a model is found in cppExamples/basic.cpp, the cppExamples directory also contains a CMakeLists.txt showing how to obtain the required headers for the KineticGas library, as well as link the library to your program.

Initializing a model

To initialize a model, include the appropriate header file, and specify the components to model with a comma separated string, as

#include "MieKinGas.h"

int main(){
    MieKinGas mie("HE,NE"); // Mixture of helium and neon.
}

The component identifiers used are equivalent to the file names of the fluid files, and are summarised here

Computing properties

The interfaces for property calculations are more or less equivalent to those used in Python. The major differences you should be aware of are

• Diffusion coefficients are returned as an Eigen::MatrixXd
  • Note: The optional dependent_idx argument to interdiffusion supports python-style negative indexing (i.e. -1 is the last component).
• Vector properties (e.g. thermal diffusion coefficients) are returned as an Eigen::VectorXd
• Frames of reference are specified with the FrameOfReference enum, found in utils.h. Valid values are
  • FrameOfReference::CoN - Center of moles
  • CoM - Center of mass (barycentric)
  • CoV - Center of volume
  • solvent - Solvent, solvent index is the dependent_idx, which defaults to the last component.
  • zarate, zarate_x, and zarate_w - See the memo
  • See the python docs and the memo for more details on definitions of the diffusion coefficients.

Selecting transfer length models

Use the methods

• void KineticGas::set_transfer_length_model(int model_id) - Set the transfer length model
• std::pair<int, std::string> KineticGas::get_transfer_length_model() - Return the current transfer length model key (int) and description (string)
• std::map<int, std::string> KineticGas::get_valid_transfer_length_models() - Get a map of valid models with descriptions

In addition, the enum TransferLengthModel in utils.h may be useful if you don’t like remembering keys. The enum is used everywhere internally, and it is heavily recommended to use it instead of manually specifying , in case keys for different models are changed in the future