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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 argument needed.

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 alternative mesh region
  -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 needed.

Fields

No field needed.

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.

boundary layer profile

Further information

Tutorial:

Source code:

History:

  • Introduced in version 1.5