[HerrSchein]

Hello everybody,

I'm trying to add the transport of a scalar for tracing the flow from one of two inlets to simpleFoam. The scalar should only be transported by convection.The equation I plan to add to the simpleFoam solver looks like this.

fvScalarMatrix tracerEqn
(
fvm::ddt(tracer) == - fvm::div(phi,tracer)
);

If I use it for solving I get a floating point exception which I guess is due to simpleFoam not being made for code containing ddt() terms which would be nonsense to do in a steady-state simulation. This being a stationary problem would make that term zero anyway so that should not be a problem. I can't figure out how to write that zero into there though.

My problem seems rather trivial to me but I can't find a solution. Does somebody here knoe how to express such an equation?