OpenFOAM中funkySetFields的安装与使用

OpenFOAM中有个setFields函数能够设置简单的初始场，其实，OpenFOAM的插件swak4foam中funkySetFields能够设置更复杂的初始条件。

funkySetFields的安装

根据不同的OpenFOAM版本，在这个网站选择安装.

以OpenFOAM 3.0.1为例：

新建一个安装文件夹

mkdir -p $FOAM_RUN
cd "$HOME/OpenFOAM/$USER-$WM_PROJECT_VERSION"

用svn安装：

svn checkout svn://svn.code.sf.net/p/openfoam-extend/svn/trunk/Breeder_2.0/libraries/swak4Foam/ swak4Foam

当然也可以试试网站中的另两种方法。

swak4foam包含下列文件或文件夹：

├── COPYING
├── debian
├── distroPatches
├── Documentation
├── Doxyfile
├── Examples
├── gtags.conf
├── Libraries
├── maintainanceScripts
├── Makefile
├── misc
├── README
├── README.md
├── releases
├── releaseTesting
├── swakConfiguration.automatic
├── swakConfiguration.centos6
├── swakConfiguration.debian
├── swakConfiguration.example
├── theFiles.sh
└── Utilities

编译

在swak4foam中输入以下命令：
./Allwmake
显示如下

This is a clean install
No file 'swakConfiguration'. Python etc won't work. See README for details
Try 'ln -s swakConfiguration.automatic swakConfiguration' for automatic configuration. BEWARE: this does not work on some systems
Checking swak4Foam-version and generating file
Swak version is 0.4.1

No 'bison' found. This is absolutely essential for swak4Foam. Can't go on
Every Linux has a binary package that installs bison (http://www.gnu.org/software/bison/). Install it. Then go on
As an alternative you can install a local copy of bison by running ./maintainanceScripts/compileRequirements.sh from the installation directory
BTW: it was listed as a requirement in the README. You read that, didn't you?


Requirements for Library not satisfied. I see no sense in going on
Check the README before you go on to ask. And search: Most likely your problem occured to 5 other people before and has been solved on the MessageBoard

根据cfd-online上的回答：
How to install swak4Foam in OF 2.3?
swak4foam >>>> INSTALLATION PROBLEM
下载文件
在swak4foam路径下输入：
maintainanceScripts/compileRequirements.sh
然后编译：
./Allwmake
终端中输入funkySetFields显示如下，说明安装成功。

llp@ubuntu:~/OpenFOAM/llp-3.0.1/swak4Foam$ funkySetFields 
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  3.0.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 3.0.1-119cac7e8750
Exec   : funkySetFields
Date   : Dec 15 2017
Time   : 00:52:30
Host   : "ubuntu"
PID    : 40573
Case   : /home/llp/OpenFOAM/llp-3.0.1/swak4Foam
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
swakVersion: 0.4.1 (Release date: 2017-05-31)
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


--> FOAM FATAL ERROR: 
funkySetFields: time/latestTime option is required


    From function main()
    in file funkySetFields.C at line 759.

FOAM exiting

使用

1、常用关键字

field //用来指定要修改的场
expression_r //用来指定表达式 
condition //用来指定上述表达式应当满足的条件 
keepPatches //用来说明是否保持原来边界条件，最好加上，不加的话，funkySetField会给所有边界为0梯度 
create   //用来说明是否是新建场 
valuePatches //用来指定那些定值边界由临近内部节点值给定
dimension //用来指定新建立场的单位 
time //用来指定funkySetField所指定的时间点

应当指出，上述关键字可以直接在控制台上输，也可以写在名字为funkySetFieldsDict（类似于setFieldsDict）中。

2、使用方法网址1 网址2
方法一直接在控制台输入
基本命令行用法
直接进入你要初始话的case中，输入类似于下面的命令。如上面的setField也可以通过下面的funkySetFields命令来实现

funkySetFields -case damBreak -time 0 -field alpha.water -expression 1 -condition "pos().x <= 0.1461 && pos().y <= 0.292"

or:

funkySetFields -case damBreak -time 0 -field alpha.water -expression " pos().x <= 0.1461 && pos().y <= 0.292 ? 1 : 0"

注意比较长的式子用单引号或者双引号隔开。上述关键字没有次序要求。
类似于setFields：

1  defaultFieldValues
2  (
3      volScalarFieldValue alpha.water 0
4  );
5  
6  regions
7  (
8      boxToCell
9      {
10         box (0 0 -1) (0.1461 0.292 1);
11         fieldValues
12         (
13             volScalarFieldValue alpha.water 1
14         );
15     }
16 );

高级命令行用法

方法二使用funkySetFieldsDict字典

C＋＋基本操作符

+,-,*,/，%， <,>,<=,>=,!=,==， &&,||，？：

OpenFOAM定义的向量操作符

&,^

圆周率常量

pi

标量函数

pow,log,exp,sqr,sqrt,sin,cos,tan

OpenFOAM中的一些函数（部分）

mag：求模 
grad ：求标量梯度 
curl ：求向量旋度 
snGrad：表面法向剃度 
div ：向量场散度 
laplaction ：求一个场的laplacian项目 
min,max ：标量场的最值 
average,integrate,sum,
reconstruct重建一个面场（产生体积场）
pos :网格中心位置矢量 
fpos ：面中心位置矢量 
face ：表面法向量场 
area：表面面积场 
vol ：网格单元体积场 
deltaT ：时间步长 
time ：当前时间

示例1

expressions
(
    initLower
    {
        field lowerPatch;
        create true;
        expression "1";
        condition "pos().y<0";
        valuePatches ( zminus );
        dimension [0 1 -1 0 0];
    }
    clearLower
    {
        field lowerPatch;
        expression "0";
        keepPatches true;  //是否保持以前边界
    }

    setTube
    {
        field tubeField;
        create true;
        expression "pos().z";
        condition "sqrt(pow(pos().x,2)+pow(pos().y,2))<0.0001";
    }
);

示例2：

expressions
 (
    circleVel
    {
        field U;
        expression "(grad(dist())^vector(0,0,-1))*mag(pos()-vector(0.05,0.05,0))/0.05";
    }
    pressure1
    {
        field p;
        expression "10.*(0.1-pos().y)";
    }
    pressure2
    {
        field p;
        expression "p+U&U";
        condition "pos().x > (max(pos().x)-min(pos().x))/2";
    }
 );

初始化水箱中z方向上的压力梯度。水箱水表面高度2.1米，底部z坐标－3.4米，总共深5.5米。

expressions
 (
    pressureWater
    {
     field p; //field to initialise
     expression "9810.*(2.1-pos().z)+100000"; 
     condition  "(pos().z<2.1) && (pos().z>=-3.4)"; //ranging from 2.1 meter to -3.4 meter
     keepPatches 1; //keep the boundary conditions that were set before
    }
 );

海面上竖直方向上风速的对数廓线分布:

expressions
 (
    WindSpeed
    {
     field U; //field to initialise
     expression "(vector(0,Ustar,0)/0.41)log(pos().z/z0_)"; 
     condition  "(pos().z<500) && (pos().z>=0)"; //ranging from 0 meter to 500 meter
     keepPatches 1; //keep the boundary conditions that were set before
    }
 );

命令：funkySetFields -time 0