From 3e41c1004e119e0776912a2e8e5e96f2e627f494 Mon Sep 17 00:00:00 2001
From: Kutalmis Bercin <kutalmis.bercin@esi-group.com>
Date: Fri, 28 Aug 2020 11:06:45 +0100
Subject: [PATCH] ENH: yPlus: add option to disable wall function contributions
(#1773)
DOC: yPlus: add mathematical expressions
TUT: yPlus: add the option example to pisoFoam/RAS/cavity
---
src/functionObjects/field/yPlus/yPlus.C | 19 +++++--
src/functionObjects/field/yPlus/yPlus.H | 49 ++++++++++++++++---
.../pisoFoam/RAS/cavity/system/FOyPlus | 3 ++
3 files changed, 60 insertions(+), 11 deletions(-)
diff --git a/src/functionObjects/field/yPlus/yPlus.C b/src/functionObjects/field/yPlus/yPlus.C
index 8fc394738e7..745b10808dc 100644
--- a/src/functionObjects/field/yPlus/yPlus.C
+++ b/src/functionObjects/field/yPlus/yPlus.C
@@ -70,7 +70,8 @@ Foam::functionObjects::yPlus::yPlus
)
:
fvMeshFunctionObject(name, runTime, dict),
- writeFile(obr_, name, typeName, dict)
+ writeFile(obr_, name, typeName, dict),
+ useWallFunction_(true)
{
read(dict);
@@ -101,10 +102,14 @@ Foam::functionObjects::yPlus::yPlus
bool Foam::functionObjects::yPlus::read(const dictionary& dict)
{
- fvMeshFunctionObject::read(dict);
- writeFile::read(dict);
+ if (fvMeshFunctionObject::read(dict) && writeFile::read(dict))
+ {
+ useWallFunction_ = dict.getOrDefault<bool>("useWallFunction", true);
- return true;
+ return true;
+ }
+
+ return false;
}
@@ -139,7 +144,11 @@ bool Foam::functionObjects::yPlus::execute()
{
const fvPatch& patch = patches[patchi];
- if (isA<nutWallFunctionFvPatchScalarField>(nutBf[patchi]))
+ if
+ (
+ isA<nutWallFunctionFvPatchScalarField>(nutBf[patchi])
+ && useWallFunction_
+ )
{
const nutWallFunctionFvPatchScalarField& nutPf =
dynamic_cast<const nutWallFunctionFvPatchScalarField&>
diff --git a/src/functionObjects/field/yPlus/yPlus.H b/src/functionObjects/field/yPlus/yPlus.H
index 6614ef33ff2..67dc199c969 100644
--- a/src/functionObjects/field/yPlus/yPlus.H
+++ b/src/functionObjects/field/yPlus/yPlus.H
@@ -31,7 +31,27 @@ Group
grpFieldFunctionObjects
Description
- Computes the near wall \f$y_1^+\f$ for turbulence models.
+ Computes the near wall \f$y_1^+\f$.
+
+ \f[
+ y_1^+ = \frac{u_* \, y_1}{\nu}
+ \f]
+
+ \f[
+ y_1^+ =
+ \frac{y_1 \sqrt{\nu_{eff} \, |\vec n \cdot \nabla \vec u_p| } }{\nu}
+ \f]
+
+ where
+ \vartable
+ y_1^+ | Wall-normal height of the first cell centre in wall units [-]
+ u_* | Friction velocity [m/s]
+ y_1 | Wall-normal height of the first cell centre [m]
+ \nu | Kinematic viscosity of fluid [m2/s]
+ \nu_{eff} | Effective patch kinematic viscosity [m2/s]
+ \vec n | Patch normal unit vector (into the domain) [-]
+ \vec u_p | Patch velocity field [m/s]
+ \endvartable
Operands:
\table
@@ -47,8 +67,11 @@ Usage
yPlus1
{
// Mandatory entries (unmodifiable)
- type yPlus;
- libs (fieldFunctionObjects);
+ type yPlus;
+ libs (fieldFunctionObjects);
+
+ // Optional entries (runtime modifiable)
+ useWallFunction true;
// Optional (inherited) entries
...
@@ -57,9 +80,13 @@ Usage
where the entries mean:
\table
- Property | Description | Type | Req'd | Dflt
- type | Type name: yPlus | word | yes | -
- libs | Library name: fieldFunctionObjects | word | yes | -
+ Property | Description | Type | Reqd | Dflt
+ type | Type name: yPlus | word | yes | -
+ libs | Library name: fieldFunctionObjects | word | yes | -
+ useWallFunction | Flag to use the local expressions of <!--
+ --> the selected wall function to compute yPlus, <!--
+ --> otherwise directly compute yPlus from flow field <!--
+ --> | bool | no | true
\endtable
The inherited entries are elaborated in:
@@ -71,6 +98,10 @@ Usage
<solver> -postProcess -func yPlus
\endverbatim
+Note
+ - \c yPlus function object operates only
+ on either wall patches or patches using a \c nutWallFunction.
+
See also
- Foam::functionObject
- Foam::functionObjects::fvMeshFunctionObject
@@ -106,6 +137,12 @@ class yPlus
public fvMeshFunctionObject,
public writeFile
{
+ // Private Data
+
+ //- Flag to use the wall function expressions to compute yPlus
+ bool useWallFunction_;
+
+
// Private Member Functions
//- File header information
diff --git a/tutorials/incompressible/pisoFoam/RAS/cavity/system/FOyPlus b/tutorials/incompressible/pisoFoam/RAS/cavity/system/FOyPlus
index f18aeee4102..fee3a7cbbb7 100644
--- a/tutorials/incompressible/pisoFoam/RAS/cavity/system/FOyPlus
+++ b/tutorials/incompressible/pisoFoam/RAS/cavity/system/FOyPlus
@@ -12,6 +12,9 @@ yPlus1
type yPlus;
libs (fieldFunctionObjects);
+ // Optional entries
+ useWallFunction true;
+
// Optional (inherited) entries
writePrecision 10;
writeToFile true;
--
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