Section: FreeSurfaceDamping

This section controls the free-surface damping physics module. The module is intended for multiphase simulations and applies relaxation near the domain boundaries to reduce wave reflections and smooth the free surface.

Example:

incflo.physics = MultiPhase FreeSurfaceDamping
FreeSurfaceDamping.vertical_velocity_damping = true
FreeSurfaceDamping.volume_fraction_damping = true
FreeSurfaceDamping.global_damping = false
FreeSurfaceDamping.length_xlo = 5.0
FreeSurfaceDamping.length_xhi = 10.0
FreeSurfaceDamping.length_ylo = 5.0
FreeSurfaceDamping.length_yhi = 5.0

FreeSurfaceDamping.vertical_velocity_damping

type: Boolean, optional, default = true

When enabled, the module damps the vertical velocity component toward zero in the active damping region.

FreeSurfaceDamping.volume_fraction_damping

type: Boolean, optional, default = false

When enabled, the module relaxes the current volume fraction field toward a smoother distribution using a local horizontal 3x3 average. If the volume fraction changes, the density field is updated consistently.

FreeSurfaceDamping.global_damping

type: Boolean, optional, default = false

When enabled, damping is applied throughout the domain. When disabled, damping is restricted to boundary zones whose widths are specified by the length_x* and length_y* parameters. Within those boundary zones, the damping strength is ramped up from zero at the edge of the damping zone to full strength at the domain boundary.

FreeSurfaceDamping.time_scale_fraction

type: Real, optional, default = 1.0

Fraction of the computed damping update to apply on each call to the method. Smaller values make the damping act more gradually. This parameter should not exceed 1 or be less than 0.

FreeSurfaceDamping.length_xlo

type: Real, mandatory when global_damping = false

Physical length of the damping zone near the low-x boundary.

FreeSurfaceDamping.length_xhi

type: Real, mandatory when global_damping = false

Physical length of the damping zone near the high-x boundary.

FreeSurfaceDamping.length_ylo

type: Real, mandatory when global_damping = false

Physical length of the damping zone near the low-y boundary.

FreeSurfaceDamping.length_yhi

type: Real, mandatory when global_damping = false

Physical length of the damping zone near the high-y boundary.