applyBoundaryLayer

Overview

The applyBoundaryLayer utility sets the velocity and turbulence-field profiles near to wall patches based on the one-seventh power law.

Usage

Synopsis

applyBoundaryLayer [OPTIONS]

Examples

Specify the boundary-layer thickness of 0.1 [m] and write optional turbulence fields:

applyBoundaryLayer -ybl 0.1 -writeTurbulenceFields

Input

Arguments

No arguments required.

Options

-Cbl <scalar>     Boundary-layer thickness as Cbl * mean distance to wall
  -case <dir>       Case directory (instead of current directory)
  -decomposeParDict <file>
                    Alternative decomposePar dictionary file
  -parallel         Run in parallel
  -region <name>    Specify mesh region (default: region0)
  -writeTurbulenceFields
                    Write the turbulence fields
  -ybl <scalar>     Specify the boundary-layer thickness
  -doc              Display documentation in browser
  -help             Display short help and exit
  -help-compat      Display compatibility options and exit
  -help-full        Display full help and exit

Files

No file input required.

Fields

No field input required.

Output

Logs

No log output.

Files

No file output.

Fields

By default, the path to write the fields is <case>/<time>/ and the utility will overwrite the local velocity field. In addition, the -writeTurbulenceFields option can be used to evaluate turbulence fields using the new velocity profile for:

Property	Description	Type
nut	Turbulence viscosity	volScalarField
epsilon	Turbulence kinetic energy dissipation rate	volScalarField
k	Turbulence kinetic energy	volScalarField
omega	Specific dissipation rate	volScalarField
nuTilda	Modified turbulence viscosit	volScalarField

Method

$$\frac{u}{U} = \left(\frac{y}{\delta}\right)^{\frac{1}{7}}$$

Where

$u$ : boundary layer velocity, [m/s]

$U$ : freestream velocity, [m/s]

$y$ : normal wall distance, [m]

$\delta$ : boundary layer thickness, [m]

The boundary layer thickness is user defined as either:

• a fixed height
• proportional to the average wall distance for the entire mesh

For example, the boundary layer profile using a freestream velocity of 1 m/s and boundary layer height of 0.05 m is shown below.

Further information

Tutorial:

• wallMountedHump

Source code:

• applyBoundaryLayer

History: Introduced in version 1.5