GfsAdaptFunction

From Gerris

GfsAdaptFunction uses a "cell cost" defined by a GfsFunction.

The syntax in parameter files is:

[ GfsAdapt ] [ GfsFunction ]

For example, the following will result in a fine mesh being used only along the interface defined by variable T:

VariableTracerVOF T
...
AdaptFunction { istep = 1 } { cmax = 0 minlevel = 5 maxlevel = 8 } (T > 0 && T < 1)

Examples

• Air-water flow around a Series 60 cargo ship

    AdaptFunction { istep = 1 } {
        cmax = 1e-2
        # Faster coarsening than with the default cfactor of 4 reduces
        # the size of the simulation
#        cfactor = 2
        # Coarse 'sponge' for x >= 1.5
        maxlevel = (x < 1.5 ? LEVEL : 4)
        minlevel = 4
    } {
        return (T > 0.)*fabs (Vorticity)*ftt_cell_size (cell)/FROUDE;
    }

• Time-reversed advection with curvature-based refinement

    AdaptFunction { istep = 1 } { cmax = 0.1 maxlevel = 8 minlevel = 6 } {
        return T > 0. && T < 1. ? ftt_cell_size (cell)*fabs (K) : 0.;
    }

• Viscous flow past a sphere

    AdaptFunction { istep = 1 } { cmax = 1e-2 maxlevel = LEVEL } {
	return (fabs(dx("U"))+fabs(dy("U")))/fabs(U)*ftt_cell_size (cell);
    }

• Shape oscillation of an inviscid droplet

    AdaptFunction { istep = 1 } {
        cmax = 0.01
        maxlevel = LEVEL
    } (T > 0 && T < 1 ? 1. : fabs (Vorticity)*ftt_cell_size (cell))