SLTS (local time step) example
 

In a lot of CFD methods it is standard practice to use local time-stepping to obtain steady-state answers much more quickly from a transient solver. I see that SLTS (Stabilised Local Time Step) is a ddt scheme that is available, but I cannot find any meaningful advice on how to use it. The source code asks for "The name of the flux field used to calculate the local time-step" as an option, and when you run the solver, it says that it wants a surfaceScalarField for this. Has anybody here used SLTS?

This should work:

ddtSchemes
{
default SLTS phi rho 0.5
}

The first term is surfaceScalarFiled the second is the density, for example if you are using buoyantBoussinesqFoam you may need to use rhok as density, and the last term is max CFL number.