Description🔗
The fan
is a general boundary condition to simulate a jump
condition between a pair of patches, using the cyclic
condition as a base.
The condition can accept user-defined fan curve of pressure rise vs velocity.
Usage🔗
The condition requires entries in both the boundary
and field files.
Boundary file🔗
<patchName>
{
type cyclic;
...
}
Field file🔗
<patchName>
{
// Mandatory entries
type fan;
jumpTable <Function1<Type>>;
// Optional entries
phi <word>;
rho <word>;
uniformJump <bool>;
nonDimensional <bool>;
// Conditional entries
// if 'nonDimensional' is true
rpm <Function1<scalar>>;
dm <Function1<scalar>>;
// Inherited entries
patchType cyclic;
...
}
where:
Property | Description | Type | Required | Default |
---|---|---|---|---|
type |
Type name: fan
|
word | yes | - |
jumpTable |
Jump dataset | Function1<Type> | yes | - |
phi |
Name of the flux transporting the field | word | no | phi |
rho |
Name of the density field for normalising the mass flux | word | no | rho |
uniformJump |
Flag to apply uniform pressure drop | bool | no | false |
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 | - |
The inherited entries are elaborated in:
- uniformJumpFvPatchField.H
-
Function1.H
- The underlying
patchType
should be set tocyclic
.
Method🔗
The non-dimensional flux is calculated as follows:
\[\phi = \frac{120 U_n}{\pi^3 d_m r_{pm}}\]The non-dimensional pressure:
\[\Psi = \frac{2 \Delta P}{\rho (\pi \omega d_m)^2}\]Property | Description |
---|---|
\(d_m\) | Fan mean diameter |
\(r_{pm}\) | Fan rpm |
\(\Delta P\) | Pressure drop |
\(\omega\) | Rotational speed [rad/s] |
The non-dimensional table should be given as \(\Psi = F(\phi)\).
Further information🔗
Tutorial:
Source code:
API:
History:
- Introduced in version 1.5