[soln-bcs-name]

Parameterises constant, or if available space (x, y, [z]) and time (t) dependent, boundary condition labelled name in the .pyfrm file with

1. type — type of boundary condition:

   ac-char-riem-inv | ac-in-fv | ac-out-fp | char-riem-inv | char-riem-inv-mass-flow | no-slp-adia-wall | no-slp-isot-wall | no-slp-wall | slp-adia-wall | slp-wall | sub-in-frv | sub-in-ftpttang | sub-out-fp | sup-in-fa | sup-out-fn

   where

   ac-char-riem-inv only works with ac-euler | ac-navier-stokes and requires

   • ac-zeta — artificial compressibility factor for boundary (increasing ac-zeta makes the boundary less reflective allowing larger deviation from the target state)

     float

   • niters — number of Newton iterations

     int

   • p — pressure

     float | string

   • u — x-velocity

     float | string

   • v — y-velocity

     float | string

   • w — z-velocity

     float | string

   ac-in-fv only works with ac-euler | ac-navier-stokes and requires

   • u — x-velocity

     float | string

   • v — y-velocity

     float | string

   • w — z-velocity

     float | string

   ac-out-fp only works with ac-euler | ac-navier-stokes and requires

   • p — pressure

     float | string

   char-riem-inv only works with euler | navier-stokes and requires

   • rho — density

     float | string

   • u — x-velocity

     float | string

   • v — y-velocity

     float | string

   • w — z-velocity

     float | string

   • p — static pressure

     float | string

   char-riem-inv-mass-flow only works with euler | navier-stokes and requires

   • rho — density

     float | string

   • u — x-velocity

     float | string

   • v — y-velocity

     float | string

   • w — z-velocity

     float | string

   • p — initial static pressure, the controller will vary this to target a mass flow rate.

     float | string

   • mass-flow-rate — target mass flow rate across the boundary.

     float | string

   • alpha — parameter between 0 and 1 for the exponentially weighted moving average of the mass flow rate.

     float | string

   • eta — parameter greater than 0 setting the strength of the controller. The appropriate strength is problem specific, and varies depending on if the simulation has been non-dimensionalised.

     float | string

   • nsteps — number of Runge-Kutta steps between activations of the controller. Typically between 10 and 500.

     int

   • tstart — start time of the mass flow controller, before this time the Riemann invariant remains fixed.

     float

   • quad-deg-{etype} — degree of quadrature rule for mass flow integration (optional).

     int

   • quad-pts-{etype} — name of quadrature rule (optional).

     string

   • file — name of a CSV file to output statistics to (optional).

     string

   • flushsteps — frequency to flush output to the CSV file (optional).

     int

   no-slp-adia-wall only works with navier-stokes

   no-slp-isot-wall only works with navier-stokes and requires

   • u — x-velocity of wall

     float

   • v — y-velocity of wall

     float

   • w — z-velocity of wall

     float

   • cpTw — product of specific heat capacity at constant pressure and temperature of wall

     float

   no-slp-wall only works with ac-navier-stokes and requires

   • u — x-velocity of wall

     float

   • v — y-velocity of wall

     float

   • w — z-velocity of wall

     float

   slp-adia-wall only works with euler | navier-stokes

   slp-wall only works with ac-euler | ac-navier-stokes

   sub-in-frv only works with navier-stokes and requires

   • rho — density

     float | string

   • u — x-velocity

     float | string

   • v — y-velocity

     float | string

   • w — z-velocity

     float | string

   sub-in-ftpttang only works with navier-stokes and requires

   • pt — total pressure

     float

   • cpTt — product of specific heat capacity at constant pressure and total temperature

     float

   • theta — azimuth angle (in degrees) of inflow measured in the x-y plane relative to the positive x-axis

     float

   • phi — inclination angle (in degrees) of inflow measured relative to the positive z-axis

     float

   sub-out-fp only works with navier-stokes and requires

   • p — static pressure

     float | string

   sup-in-fa only works with euler | navier-stokes and requires

   • rho — density

     float | string

   • u — x-velocity

     float | string

   • v — y-velocity

     float | string

   • w — z-velocity

     float | string

   • p — static pressure

     float | string

   sup-out-fn only works with euler | navier-stokes

Example:

[soln-bcs-bcwallupper]
type = no-slp-isot-wall
cpTw = 10.0
u = 1.0

Simple periodic boundary conditions are supported; however, their behaviour is not controlled through the .ini file, instead it is handled at the mesh generation stage. Two faces may be tagged with periodic_x_l and periodic_x_r, where x is a unique identifier for the pair of boundaries. Currently, only periodicity in a single cardinal direction is supported, for example, the planes (x,y,0) and (x,y,10).