# Title: Rayleigh-Taylor instability
#
# Description:
#
# A classical test case for the flow of two fluids of different
# densities. A sinusoidal interface separates the two fluids. The
# heavier fluid is on top. A mushroom-shaped instability develops in
# time as illustrated on Figure \ref{evolution}.
# 
# \begin{figure}[htbp]
# \caption{\label{evolution}Evolution of the interface.}
# \begin{center}
# \begin{tabular}{ccccc}
# \includegraphics[width=0.15\hsize]{t-0.eps} &
# \includegraphics[width=0.15\hsize]{t-0.7.eps} &
# \includegraphics[width=0.15\hsize]{t-0.8.eps} &
# \includegraphics[width=0.15\hsize]{t-0.9.eps} &
# \includegraphics[width=0.15\hsize]{t-1.eps} \\
# $t=0$ & $t=0.7$ & $t=0.8$ & $t=0.9$ & $t=1.0$
# \end{tabular}
# \end{center}
# \end{figure}
#
# \begin{figure}[htbp]
# \caption{\label{movie}MPEG movies of the tracer and vorticity fields.}
# \begin{center}
# \begin{tabular}{cc}
# \htmladdnormallinkfoot{\includegraphics[width=0.2\hsize]{t.eps}}{t.mpg} &
# \htmladdnormallinkfoot{\includegraphics[width=0.2\hsize]{vort.eps}}{vort.mpg}
# \end{tabular}
# \end{center}
# \end{figure}
#
# Author: St\'ephane Popinet
# Command: gerris2D rt.gfs | gfsview2D rt.gfv
# Version: 1.1.0
# Required files: rt.gfv
# Running time: 12 minutes
# Generated files: t.mpg vort.mpg t.eps vort.eps t-0.eps t-0.7.eps t-0.8.eps t-0.9.eps t-1.eps
#
4 3 GfsSimulation GfsBox GfsGEdge {} {
  Time { end = 1 dtmax = 5e-3 }
  Refine 7

  # The tracer T is used to track both phases
  VariableTracerVOF {} T
 
  # The initial sinusoidal interface (translated by 0.5 along the y-axis)
  InitFraction {} T (0.05*cos (2.*M_PI*x) + y) { ty = 0.5 }

  AdaptVorticity { istep = 1 } { maxlevel = 7 cmax = 2e-2 }
  AdaptGradient { istep = 1 } { maxlevel = 7 cmax = 1e-2 } T

  # The dynamic viscosity for both phases
  SourceViscosity {} 0.00313

  # This defines the inverse of the density of the fluids as a
  # function of T
  PhysicalParams { alpha = 1./(T*1.225 + (1. - T)*0.1694) }

  # We also need gravity
  Source {} V -9.81

  OutputTime { istep = 10 } stderr
  OutputBalance { istep = 10 } stderr
  OutputProjectionStats { istep = 10 } stderr
  OutputDiffusionStats { istep = 10 } stderr
  OutputPPM { istep = 2 } { ppm2mpeg > vort.mpg} {
    min = -30 max = 30 v = Vorticity
  }
  OutputPPM { istep = 2 } { ppm2mpeg > t.mpg } {
    min = 0 max = 1 v = T
  }
  OutputPPM { start = end } { convert -colors 256 ppm:- vort.eps } {
    min = -30 max = 30 v = Vorticity
  }
  OutputPPM { start = end } { convert -colors 256 ppm:- t.eps } {
    min = 0 max = 1 v = T
  }
  OutputTiming { start = end } stderr
  OutputSimulation { step = 0.1 } stdout
  EventScript { start = 0 } { echo "Save t-0.eps { format = EPS }" }
  EventScript { start = 0.7 step = 0.1 } { echo "Save t-$GfsTime.eps { format = EPS }" }
}
GfsBox {}
GfsBox {}
GfsBox {}
GfsBox {}
1 2 top
2 3 top
1 4 bottom