Description🔗
The fanPressure
is a pressure boundary condition to assign either a pressure
inlet or outlet total pressure condition for a fan. The condition sets the
static pressure from a definition of the total pressure and pressure drop as a
function of volumetric flow rate across the patch.
The non-dimensional flux is calculated as follows:
\[phi = \frac{4 \dot{m}}{\rho \pi^2 d_m^3 \omega}\]The non-dimensional flux is calculated as follows:
\[\Psi = \frac{2 \Delta P}{\rho (\pi \omega d_m)}\]Property | Description |
---|---|
\(d_m\) | Fan mean diameter [m] |
\(\Delta P\) | Pressure drop |
\(\omega\) | Rotational speed [rad/s] |
\(\dot{m}\) | Mass flow rate |
The non-dimensional table should be given as \(\Psi = F(\phi)\).
The condition sets the static pressure at the patch \(p_p\) based on a specification of the total pressure, \(p_0\), and pressure drop, \(p_d\), specified as a function of the volumetric flow rate.
\[p_p = p_0 - p_d\]Usage🔗
The condition requires entries in both the boundary
and field files.
Boundary file🔗
<patchName>
{
type patch;
...
}
Field file🔗
<patchName>
{
// Mandatory entries
type fanPressure;
fanCurve <Function1<scalar>>;
direction <word>;
// Optional entries
nonDimensional <bool>;
// Conditional entries
// if 'nonDimensional' is true
rpm <Function1<scalar>>;
dm <Function1<scalar>>;
// Inherited entries;
...
}
where:
Property | Description | Type | Required | Default |
---|---|---|---|---|
type |
Type name: fan
|
word | yes | - |
fanCurve |
Dataset of pressure vs flow rate | Function1<scalar> | yes | - |
direction |
Direction of flow through fan | word | yes | - |
nonDimensional |
Flag to use non-dimensional curves | bool | no | false |
rpm |
Fan rpm (for non-dimensional curve) | Function1<scalar> | conditional | - |
dm |
Fan mean diameter (for non-dimensional curve) | Function1<scalar> | conditional | - |
Options for the direction
entry:
Property | Description |
---|---|
in |
Into the fan |
out |
Out of the fan |
The inherited entries are elaborated in:
- Foam::totalPressureFvPatchScalarField
- For compatibility with older versions (OpenFOAM-v2006 and earlier),
a missing
fanCurve
keyword is treated as atableFile
and makes thefile
keyword mandatory.
Further information🔗
Tutorial:
Source code:
API:
History:
- Introduced in version 1.5