syringePressure

Description

The syringePressure is a boundary condition that provides a pressure condition, obtained from a zero-D model of the cylinder of a syringe.

The syringe cylinder is defined by its initial volume, piston area and velocity profile specified by regions of constant acceleration, speed and deceleration. The gas in the cylinder is described by its initial pressure and compressibility which is assumed constant, i.e. isothermal expansion/compression.

Usage

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

Boundary file

<patchName>
{
    type            patch;
    ...
}

Field file

<patchName>
{
    // Mandatory entries
    type            syringePressure;
    Ap              <scalar>;
    Sp              <scalar>;
    VsI             <scalar>;
    tas             <scalar>;
    tae             <scalar>;
    tds             <scalar>;
    tde             <scalar>;
    psI             <scalar>;
    psi             <scalar>;
    ams             <scalar>;

    // Optional entries
    phi             <word>;

    // Inherited entries
    ...
}

where:

Property	Description	Type	Required	Default
type	Type name: syringePressure	word	yes	-
Ap	Syringe piston area [m^2]	scalar	yes	-
Sp	Syringe piston speed [m/s]	scalar	yes	-
VsI	Initial syringe volume [m^3]	scalar	yes	-
tas	Start of piston acceleration [s]	scalar	yes	-
tae	End of piston acceleration [s]	scalar	yes	-
tds	Start of piston deceleration [s]	scalar	yes	-
tde	End of piston deceleration [s]	scalar	yes	-
psI	Initial syringe pressure [Pa]	scalar	yes	-
psi	Gas compressibility [m^2/s^2]	scalar	yes	-
ams	Added (or removed) gas mass [kg]	scalar	yes	-
phi	Name of flux field	word	no	phi

The inherited entries are elaborated in:

• Foam::fixedValueFvPatchField

Further information

Tutorial:

• N/A

Source code:

• syringePressure

API:

• Foam::syringePressureFvPatchScalarField

History: Introduced in version 1.5