The unreliable extrapolateProfile option has been replaced by the more flexible
and reliable profile option which allows the velocity profile to be specified as
a Function1 of the normalised distance to the wall. To simplify the
specification of the most common velocity profiles the new laminarBL (quadratic
profile) and turbulentBL (1/7th power law) Function1s are provided.
In addition to the new profile option the flow rate can now be specified as a
meanVelocity, volumetricFlowRate or massFlowRate, all of which are Function1s of
time.
The following tutorials have been updated to use the laminarBL profile:
multiphase/multiphaseEulerFoam/laminar/titaniaSynthesis
multiphase/multiphaseEulerFoam/laminar/titaniaSynthesisSurface
The following tutorials have been updated to use the turbulentBL profile:
combustion/reactingFoam/Lagrangian/verticalChannel
combustion/reactingFoam/Lagrangian/verticalChannelLTS
combustion/reactingFoam/Lagrangian/verticalChannelSteady
compressible/rhoPimpleFoam/RAS/angledDuct
compressible/rhoPimpleFoam/RAS/angledDuctLTS
compressible/rhoPimpleFoam/RAS/squareBendLiq
compressible/rhoPorousSimpleFoam/angledDuctImplicit
compressible/rhoSimpleFoam/angledDuctExplicitFixedCoeff
compressible/rhoSimpleFoam/squareBend
compressible/rhoSimpleFoam/squareBendLiq
heatTransfer/chtMultiRegionFoam/shellAndTubeHeatExchanger
heatTransfer/chtMultiRegionFoam/shellAndTubeHeatExchanger
incompressible/porousSimpleFoam/angledDuctImplicit
incompressible/porousSimpleFoam/straightDuctImplicit
multiphase/interFoam/RAS/angledDuct
Class
Foam::flowRateInletVelocityFvPatchVectorField
Description
Velocity inlet boundary condition creating a velocity field with
optionally specified profile normal to the patch adjusted to match the
specified mass flow rate, volumetric flow rate or mean velocity.
For a mass-based flux:
- the flow rate should be provided in kg/s
- if \c rho is "none" the flow rate is in m3/s
- otherwise \c rho should correspond to the name of the density field
- if the density field cannot be found in the database, the user must
specify the inlet density using the \c rhoInlet entry
For a volumetric-based flux:
- the flow rate is in m3/s
Usage
\table
Property | Description | Required | Default value
massFlowRate | Mass flow rate [kg/s] | no |
volumetricFlowRate | Volumetric flow rate [m^3/s]| no |
meanVelocity | Mean velocity [m/s]| no |
profile | Velocity profile | no |
rho | Density field name | no | rho
rhoInlet | Inlet density | no |
alpha | Volume fraction field name | no |
\endtable
Example of the boundary condition specification for a volumetric flow rate:
\verbatim
<patchName>
{
type flowRateInletVelocity;
volumetricFlowRate 0.2;
profile laminarBL;
}
\endverbatim
Example of the boundary condition specification for a mass flow rate:
\verbatim
<patchName>
{
type flowRateInletVelocity;
massFlowRate 0.2;
profile turbulentBL;
rho rho;
rhoInlet 1.0;
}
\endverbatim
Example of the boundary condition specification for a volumetric flow rate:
\verbatim
<patchName>
{
type flowRateInletVelocity;
meanVelocity 5;
profile turbulentBL;
}
\endverbatim
The \c volumetricFlowRate, \c massFlowRate or \c meanVelocity entries are
\c Function1 of time, see Foam::Function1s.
The \c profile entry is a \c Function1 of the normalised distance to the
wall. Any suitable Foam::Function1s can be used including
Foam::Function1s::codedFunction1 but Foam::Function1s::laminarBL and
Foam::Function1s::turbulentBL have been created specifically for this
purpose and are likely to be appropriate for most cases.
Note
- \c rhoInlet is required for the case of a mass flow rate, where the
density field is not available at start-up
- The value is positive into the domain (as an inlet)
- May not work correctly for transonic inlets
- Strange behaviour with potentialFoam since the U equation is not solved
See also
Foam::fixedValueFvPatchField
Foam::Function1s::laminarBL
Foam::Function1s::turbulentBL
Foam::Function1s
Foam::flowRateOutletVelocityFvPatchVectorField
The FOAM file format has not changed from version 2.0 in many years and so there
is no longer a need for the 'version' entry in the FoamFile header to be
required and to reduce unnecessary clutter it is now optional, defaulting to the
current file format 2.0.
so that they operate in the conventional manner in a right-handed coordinate
system:
//- Rotational transformation tensor about the x-axis by omega radians
// The rotation is defined in a right-handed coordinate system
// i.e. clockwise with respect to the axis from -ve to +ve
// (looking along the axis).
inline tensor Rx(const scalar& omega)
//- Rotational transformation tensor about the y-axis by omega radians
// The rotation is defined in a right-handed coordinate system
// i.e. clockwise with respect to the axis from -ve to +ve
// (looking along the axis).
inline tensor Ry(const scalar& omega)
//- Rotational transformation tensor about the z-axis by omega radians
// The rotation is defined in a right-handed coordinate system
// i.e. clockwise with respect to the axis from -ve to +ve
// (looking along the axis).
inline tensor Rz(const scalar& omega)
//- Rotational transformation tensor about axis a by omega radians
// The rotation is defined in a right-handed coordinate system
// i.e. clockwise with respect to the axis from -ve to +ve
// (looking along the axis).
inline tensor Ra(const vector& a, const scalar omega)
Vertices are generated using run time compilation functionality.
File duplication avoided by placement in:
tutorials/resources/blockMesh/sloshingTank2D
tutorials/resources/blockMesh/sloshingTank3D
For example in the new tutorial case:
tutorials/incompressible/pimpleFoam/laminar/pitzDailyPulse
a cosine bell velocity pulse is specified at the inlet by directly defining the
code for it:
inlet
{
type uniformFixedValue;
uniformValue coded;
name pulse;
codeInclude
#{
#include "mathematicalConstants.H"
#};
code
#{
return vector
(
0.5*(1 - cos(constant::mathematical::twoPi*min(x/0.3, 1))),
0,
0
);
#};
}
which is then compiled automatically and linked into the running pimpleFoam
dynamically and executed to set the inlet velocity.
