∇

Description

The variableHeightFlowRateInletVelocity is a boundary condition that provides a velocity boundary condition for multphase flow based on a user-specified volumetric flow rate.

The flow rate is made proportional to the phase fraction alpha at each face of the patch and alpha is ensured to be bound between 0 and 1.

Usage

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

Boundary file 

<patchName>
{
    type            patch;
    ...
}

Field file 

<patchName>
{
    // Mandatory entries
    type            variableHeightFlowRateInletVelocity;
    flowRate        <Function1<scalar>>;
    alpha           <word>;

    // Inherited entries;
    ...
}

where:

Property Description Type Required Default
type Type name: variableHeightFlowRateInletVelocity word yes -
flowRate Volumetric flow rate [m^3/s] Function1<scalar> yes -
alpha Name of phase-fraction field word no alpha

The inherited entries are elaborated in:

  • fixedValueFvPatchField.H

  • Function1.H

  • The value is positive into the domain.
  • The condition may not work correctly for transonic inlets.
  • Strange behaviour with potentialFoam since the momentum equation is not solved.

Further information

Tutorial:

Source code:

API:

History:

  • Introduced in version 2.1.1