# WAVE_DAMPING_SOURCE

Specifies a volumetric momentum source term to damp surface waves.

AcuSolve Command

## Syntax

WAVE_DAMPING_SOURCE {parameters...}

## Qualifier

This command has no qualifier.

## Parameters

wave_damping_type (enumerated) (=none)
Type of wave damping to be applied. If none, no damping is applied.
none
No damping.
linear
Linear damping model is applied.
wave_damping_distance or dist real (=0)
Distance from the outlet surface where the damping source term is active.
wave_damping_coefficient or coef real (=10)
Coefficient multiplying the damping source term.

## Description

This command is used to damp a surface wave in a multiphase flow problem by adding momentum source per unit volume to the momentum equation along the direction of gravity. The momentum source per unit volume term takes the following form:

(1)
$S\left(x\right)=-C\text{\hspace{0.17em}}\rho \text{\hspace{0.17em}}|{U}_{z}|{\left(\frac{x-{x}_{O}}{{x}_{D}}\right)}^{2}$

where C is the wave damping coefficient, $\rho$ is the density, ${U}_{Z}$ is the velocity component along gravity, x is the local coordinate where the source term is being applied, ${x}_{D}$ and ${x}_{0}$ are the wave damping distance and the coordinate of the outlet surfaces, respectively.

Wave damping with a linear model can be specified as follows:
WAVE_DAMPING_SOURCE {
wave_damping_type	         = linear
wave_damping_distance	 = 5
wave_damping_coefficient     = 10
}

Optionally, the outlet surface can be excluded from the damping zone calculation by setting the boolean wave_damping to "off" within the SIMPLE_BOUNDARY_CONDITION command.