tracer.h

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/** @file tracer.h
 */
/**
# Tracer advection event
 
This event integrates advection equations of the form
\f[
\partial_tf_i+\mathbf{u_f}\cdot\nabla f_i=0
\f]
where \f$\mathbf{u_f}\f$ is the velocity field and \f$f_i\f$ are a list of
passive tracers.
 
The `tracers` list is defined elsewhere (typically by the user), the
vector field `uf` and the timestep `dt` are defined by a
solver. */
 
extern scalar * tracers;
extern vector uf;
extern double dt;
 
/**
On adaptive meshes, tracers need to use linear interpolation (rather
than the default bilinear interpolation) to ensure conservation when
refining cells. */
 
#if TREE
/** @brief Event: defaults (i = 0) */
void event_defaults (void) {
  for (int _s = 0; _s < 1; _s++) /* scalar in tracers */ {
#if EMBED
    s.refine = refine_embed_linear;
    set_prolongation (s, refine_embed_linear);
#else
    s.refine  = refine_linear;
#endif
    set_restriction (s, restriction_volume_average);
  }
}
#endif
 
/**
The integration is performed using the Bell-Collela-Glaz scheme. */
 
#include "bcg.h"
 
/** @brief Event: tracer_advection (i++,last) */
void event_tracer_advection (void) {
  advection (tracers, uf, dt);
}
 
/**
VOF advection happens here. */
 
event vof (i++, last);
 
/**
Diffusion can be added by overloading this hook. */
 
event tracer_diffusion (i++,last);