VOF Wave Type Reference

The VOF Waves model supports the following VOF wave types: Flat, First Order, Fifth Order, Superposition, Cnoidal, Irregular, and Linked.

Table 1. VOF Wave Type Family Reference
Model Names and Abbreviations	Flat Wave		Flat
	First Order Wave		First
	Fifth Order Wave		Fifth
	Cnoidal Wave		Cnoid
	Superposition Wave		Supp
	First Order Superposing Wave		FirstSupp
	User Defined		UDW
	Irregular Wave		Irreg
	Linked Wave		Link
Theory	See VOF Waves Formulation.
Provided By	[physics continuum] > Models > VOF Waves > Waves (Right-click menu: New > [wave type])
Example Node Path	Continua > Physics 1 > Models > VOF Waves > Waves > [wave type]
Requires	The VOF Waves model activated.
Properties	See Property Lookup for VOF Wave Types.
Activates	Model Controls (child nodes)	Wave Length Specification Wave Period Specification SubWaves Free Surface Elevation Wave Velocity JONSWAP Specification See Child Nodes.
	Field Functions	Hydrostatic Pressure of [VofWave Name] Relative Zone Distance Velocity of [VofWave Name] VofWave Damping Factor Volume Fraction of Heavy Fluid of [VofWave Name] Volume Fraction of Light Fluid of [VofWave Name] See Field Functions.

Property Lookup for VOF Wave Types


	Flat	First	Fifth	Supp	FirstSupp	Cnoid	UDW	Irreg	Link
Point on Water Level Defines the mean water level when the simulation is initialized. If First Wave Front Setting is activated, this setting also defines the position of the leading front of the wave. For a flat VOF wave, this property defines the position of the water surface (that is, the water level).	✓	✓	✓	✓		✓	✓
Vertical Direction The vector normal to the mean water surface.	✓	✓	✓	✓		✓	✓
Current Velocity of the water or other heavy fluid.	✓	✓	✓	✓		✓	✓
Wind Velocity of the air or other light fluid.	✓	✓	✓	✓		✓	✓
Light Fluid Density This property is required for the hydrostatic field function that is created automatically with the wave. The default value is for air. If you are simulating any other substance, change this value manually.	✓	✓	✓	✓		✓	✓
Heavy Fluid Density This property is required for the hydrostatic field function that is created automatically with the wave. The default value is for water. If you are simulating any other substance, change this value manually.	✓	✓	✓	✓		✓	✓
Advancing Direction Direction traveled by the wave.		✓	✓		✓	✓	✓	✓
Amplitude Height of the wave crest.		✓			✓
Specification Type The quantity to use in defining the length or duration of the wave. Wave Length The wave is defined by its wavelength. A Wave Length Specification node is added as a child node. Wave Period The wave is defined by its time period. A Wave Period Specification node is added as a child node.		✓	✓		✓	✓
Deep Water Approximation When this option is activated (default), the dispersion relation for waves is independent of the water (or other heavy fluid) depth (see Eqn. (326)). When this option is deactivated, Eqn. (325) applies.		✓		✓
First Wave Front Setting When this option is activated (default), the Point on Water Level setting defines both the mean water level and the start of the wave. The first wave peak exists at a distance of wavelength/4 in the receding direction. For higher-order waves the Point on Water Level may not be at the free surface. For more information, see Setting the First Wave Front Position. There is only flat water in the Advancing Direction from the specified point. When this option is deactivated, the Point on Water Level setting defines only the mean water level. Waves are present in the entire domain at initialization and a wave peak is positioned at the origin of the advancing direction.		✓	✓	✓		✓
Additional Velocity This velocity is added to the combined velocity value that the current, wind, and wave predict. When solving for the flow around a moving vessel in the reference frame of the vessel, set this value to the inverse of the velocity of the vessel.			✓			✓
Wave Height Vertical distance from crest to trough.			✓			✓
Water Depth Depth of the body of water being simulated.			✓			✓
Phase The initial wave phase at $t$ = 0s for the particular partial wave. This property is used to describe the phase difference between the different partial waves. The wave phase is the fraction of a wave cycle that is measured in radians.					✓
Enabled When activated, the effects of this wave are included in the simulation.					✓
Order Specifies the order of the cnoidal wave solution. You can choose to include up to five terms in the calculation, by selecting the corresponding value (First order – Fifth order). Terms higher than the specified order of approximation are neglected. Alternatively, you can use Aitken transformations to improve convergence for the full series of terms in the calculation.						✓
Significant Wave Height Defined as the average height (trough to crest) of the highest one-third waves.								✓
Peak Wave Period The wave period that is determined by the inverse of the frequency at which a wave energy spectrum has its maximum value.								✓
Spectrum Type The quantity to use in defining the length or duration of the wave: Pierson-Moskowitz The Pierson-Moskowitz spectrum was proposed originally for a fully developed sea. JONSWAP The JONSWAP spectrum extends the Pierson-Moskowitz spectrum to include fetch limited seas, describing developing sea states. A JONSWAP Specification child node is added.								✓
Number of Frequencies Number of partial waves that are used to create the irregular wave. The wave amplitudes of the partial wave are computed according to the wave spectrum.								✓
Test Option When this property is activated, the random number generator uses a fixed seed. This allows you to perform repeated runs with the same wave pattern.								✓
Referenced Vof Wave Selects the reference VOF wave for the linked VOF wave. Only waves that compute field functions can be selected. It is not possible to use another linked VOF wave as reference.									✓

Child Nodes

The individual wave nodes can have the following child nodes:

Wave Length Specification

Specifies the wavelength. The corresponding wave period is displayed when the simulation has been initialized.

The Wave Length Specification properties are:

WaveLength
The wavelength $λ$ in Eqn. (324).
WavePeriod
The wave period $T$ in Eqn. (323) (read only).

This node appears when the Specification Type property of the wave is set to Wave Length. Applies to First Order, Fifth Order, and Cnoidal wave types only.

Wave Period Specification

Specifies the wave period. The corresponding wavelength is displayed when the simulation has been initialized.

The Wave Period Specification properties are:

WavePeriod
The wave period $T$ in Eqn. (323).
WaveLength
The wavelength $λ$ in Eqn. (324) (read only).

This node appears when the Specification Type property of the wave is set to Wave Period. Applies to First Order, Fifth Order, and Cnoidal wave types only.

SubWaves

This node is the manager node for the first order superposition waves that comprise a superposition wave.

The New option on the right-click menu lets you create the necessary first order superposition waves.

Free Surface Elevation

Specifies the free surface elevation for the user defined wave. This property must be set to the mapped free surface elevation field function as defined by the free surface elevation data mapper.

Applies to User Defined Waves only.

Wave Velocity

Specifies the velocity profile for the user defined wave. Each velocity component must be set to the mapped velocity component field function as defined by the velocity data mapper.

Applies to User Defined Waves only.

JONSWAP Specification

The JONSWAP specification lets you set peak shapes and spectral widths for the random wave. This node appears under an irregular wave node when the Spectrum Type property of the irregular wave is set to JONSWAP.

See JONSWAP Specification Properties.

Applies to Irregular wave types only.

JONSWAP Specification Properties

The JONSWAP spectrum extends the Pierson-Moskowitz spectrum to include fetch limited seas, describing developing sea states. This spectrum is expected to be a reasonable model for the following (in SI units):

$3.6 < \frac{Peak Wave Period}{\sqrt{Significant Wave Height}} < 5$

Peak Shape Parameter: Sets the peak shape, $γ$ in Eqn. (333). Average value is $γ$ = 3.3.
Spectral Width A: Sets $σ_{a}$ (see Eqn. (333)). Average value is 0.07.
Spectral Width B: Sets $σ_{b}$ (see Eqn. (333)). Average value is 0.09.

Field Functions

These field functions are added when any VOF wave is created. These field functions define initial conditions and boundary conditions for objects that are floating in the heavy fluid (typically water).

Hydrostatic Pressure of [VofWave Name]: Hydrostatic pressure of a particular VOF wave. This setting can be used to initialize the pressure field and on pressure boundaries.
Velocity of [VofWave Name]: The velocity vector field of a particular VOF wave. This setting can be used for initial conditions and for the velocity specification on boundaries.
Volume Fraction of Heavy Fluid of [VofWave Name]: Volume fraction of heavy fluid (such as water) of a particular VOF wave. This setting can be used for the initial volume fraction and for the volume fraction specification at boundaries.
Volume Fraction of Light Fluid of [VofWave Name]: Volume fraction of light fluid (such as air) of a particular VOF wave. This setting can be used for the initial volume fraction and for the volume fraction specification at boundaries.