SRFFreestreamVelocity

Description

The SRFFreestreamVelocity is a boundary condition that provides freestream velocity condition to be used in conjunction with the single rotating frame (SRF) model (see: SRFModel class).

Given the free stream velocity in the absolute frame, the condition applies the appropriate rotation transformation in time and space to determine the local velocity using:

$$\u_p = cos(\theta) \u_{Inf} + sin(\theta) (n \times \u_{Inf}) - \u_{p,srf}$$

where:

Property	Description
$\u_p$	Patch velocity [m/s]
$\u_{Inf}$	Free stream velocity in the absolute frame [m/s]
$\theta$	Swept angle [rad]
$n$	Axis direction of the SRF
$\u_{p,srf}$	SRF velocity of the patch [m/s]

Usage

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

Boundary file

<patchName>
{
    type            patch;
    ...
}

Field file

<patchName>
{
    // Mandatory entries
    type            SRFFreestreamVelocity;
    UInf            <vector>;

    // Optional entries
    relative        <bool>;

    // Inherited entries;
    ...
}

where:

Property	Description	Type	Required	Default
type	Type name: SRFFreestreamVelocity	word	yes	-
UInf	Velocity of the free stream in the absolute frame	vector	yes	-
relative	Flag to decide if the supplied inlet value relative to the SRF	bool	no	false

The inherited entries are elaborated in:

• inletOutletFvPatchFields.H

Further information

Tutorial:

• rotor2D

Source code:

• SRFFreestreamVelocityFvPatchVectorField

API:

• Foam::SRFFreestreamVelocityFvPatchVectorField

History: Introduced in version 2.0.0