Untitled

-- title: phaseHydrostaticPressure copyright:

• Copyright (C) 2023 OpenCFD Ltd. tags:
• boundary conditions menu_id: boundary-conditions-phaseHydrostaticPressure license: CC-BY-NC-ND-4.0 menu_parent: boundary-conditions-general group: boundary-conditions-general

---

Description

The phaseHydrostaticPressure is a generic boundary condition that provides a phase-based hydrostatic pressure condition, calculated as:

$$p_{hyd} = p_{ref} + \rho g (x - x_{ref})$$

where:

Property	Type
$p_{hyd}$	Hyrostatic pressure [Pa]
$p_{ref}$	Reference pressure [Pa]
$x_{ref}$	Reference point in Cartesian coordinates
$\rho$	Density (assumed uniform)
$g$	Acceleration due to gravity [m/s2]

The values are assigned according to the phase-fraction field:

• 1: apply $p_{hyd}$
• 0: apply a zero-gradient condition

Usage

The condition requires entries in both the boundary and field files.

Boundary file

<patchName>
{
    type            mappedPatch;
    ...
}

Field file

<patchName>
{
    // Mandatory entries
    type            phaseHydrostaticPressure;
    rho             <scalar>;
    pRefValue       <scalar>;
    pRefPoint       <vector>;

    // Optional entries
    phaseFraction   <word>;

    // Inherited entries
    ...
}

where:

Property	Description	Type	Required	Default
type	Type name: phaseHydrostaticPressure	word	yes	-
rho	Constant value of density in the far field	scalar	yes	-
pRefValue	Reference pressure [Pa]	scalar	yes	-
pRefPoint	Reference pressure location	vector	yes	-
phaseFraction	Name of phase-fraction field	word	no	alpha

The inherited entries are elaborated in:

• Foam::mixedFvPatchField

Further information

Tutorial:

• N/A

Source code:

• phaseHydrostaticPressure

API:

• Foam::phaseHydrostaticPressureFvPatchScalarField

History: Introduced in version 2.1.1