Simscape Two phase domain - concepts and logic

A two phase domain has been included in the MATLAB 2015b release. Although, the source code for different blocks in 2P domain are visible, one is unable to understand the logic and concepts behind this type of modeling For e.g in the two_port_steady.ssc, step functions are used to smooth the mass flow rate. What does this mean? Can anyone recommend a theoretical source or literature to understand these modeling concepts? It want to further extend the library with self-built components and the logic behind these is necessary to understand and model the components.

Answer 1

[Yifeng Tang]

The general principles of the two-phase domain are conservation of mass, momentum, and energy, just like the gas, moist-air, and thermal liquid domains. The key equations are documented in the Help of each block. The fluid property table look-up in two-phase is more complicated because of the phase change.

These domains also share a smoothed upwind scheme at the nodes. The step and smooth functions you noticed are to implement this numerical scheme.