Run the asymptotic-preserving two-fluid case

The isothermal two-fluid asymptotic-preserving (AP) case lives in adc_cases. It carries its own just-in-time C++ and is loaded through ctypes, so it is a good example of a custom case built on the adc_cpp headers.

Prerequisites

• The pops Python module, built from adc_cpp. See Installation.

• A local clone of adc_cases. A C++ compiler is needed because the case compiles its own kernel.

Run it

1. Clone adc_cases and enter the case folder:

   git clone https://github.com/wolf75222/adc_cases.git
   cd adc_cases/two_fluid_ap
   

2. Run the case:

   python run.py
   

   The script builds the case kernel, advances the two-fluid model, and writes its figures (the AP-versus-explicit comparison) to the case folder.

What it demonstrates

Two isothermal fluids coupled through the electric field, integrated with an asymptotic-preserving scheme that stays stable and accurate as the stiff parameter shrinks, where a plain explicit scheme would need a vanishing time step.

Learn more

• The case in adc_cases: two_fluid_ap.

• The stiff-source idea: Operator splitting, IMEX and Schur condensation.

• Multiple species: Multi-block and multi-species systems.