'ac' and boundary conditions meanings

General
1

Dear All,

I am new to PyFR and have searched on line to find if there is any explanation of

  • boundary conditions, such like 'ac-in-fv' | 'ac-out-fp' | 'char-riem-inv' | 'sub-in-frv' | 'sub-in-ftpttang' | 'sub-out-fp' | 'sup-in-fa' | 'sup-out-fn'

However, I did not find any.

And if I want to apply a gradient boundary condition or transmissive boundary condition, what should I do then?

Besides, what does ac mean in terms like ac-in-fv and 'ac-euler' | 'ac-navier-stokes'?

Thank you all in advance.

Cheers,
Henry

2

ac stands for artificial compressibility, the method PyFR uses for solving the incompressible Euler or Navier-Stokes equations.

Cheers,
Frank

3

Hi Frank,

Thank you very much. May I ask if you know anything about the boundary conditions I mentioned above?

Cheers,
Henry

在 2017年5月26日星期五 UTC+10下午6:38:30，Фрэнк Малдун写道：

4

Hi Henry,

You can find descriptions of the boundary conditions and their required user inputs within the User Manual. You can either create a local copy yourself using Python’s sphinx package and the local documentation files contained within the doc directory of PyFR’s root directory, or a current copy of it can be found on PyFR’s website at http://pyfr.org/user_guide.php.

As Frank has already indicated the ac prefix is used to denote the artificial compressibility scheme used in PyFR’s incompressible solver. The others describe boundary conditions for the compressible solver. There are conditions for riemann characteristic invariant, no-slip adiabatic walls, no-slip isothermal walls, slip walls, subsonic inflow in which rho and velocity are prescribed, subsonic inflow in which total pressure and total temperature are prescribed, subsonic outflow in which static pressure is prescribed, supersonic inflow, and supersonic outflow. Hope this helps.

Best Regards,

Zach Davis