How to add tracer transport in Saint-Venant (shallow water) simulations

[Godunov CIR]

Hello all,

I know that there are several examples and tests with tracer added (such as Bénard–von Kármán Vortex Street for flow around a cylinder), but as the source code of the tracer advection "tracer.h" suggests, the tracer advection should work with BCG scheme (since "bcg.h" is included and the function "advection" of "bcg.h" is used), which means that we could only add tracers in Navier-Stokes equations. However, there are some circumstances in shallow water simulations requiring us to add tracers and in these cases, and it is not easy to add tracers in the simulations. Although some approximate Riemann solvers could support tracers, it is not trivial to code the passive scalar transport in the Saint-Venant solver ("saint-venant.h") in Basilisk.

So could anyone suggest a proper way to add tracers in Saint-Venant (shallow water) simulations?

Thanks in advance.

Geoffery

[Stephane Popinet]

> So could anyone suggest a proper way to add tracers in Saint-Venant
> (shallow water) simulations?

If you use the multi-layer solver, you can easily solve Saint-Venant and
add tracers. See

http://basilisk.fr/src/layered/hydro.h

and

http://basilisk.fr/src/layered/nh.h#setup

for an example of how to add tracers.

cheers,

Stephane

[Godunov CIR]

@Stephane Popinet, Thanks to the answer. That really helps.