个人学习用，总结、整理了网上一些controlDict解析

1 文件结构

一个例子:

//文件说明
{
    version     2.0;                //版本号
    format      ascii;              //文本格式
    class       dictionary;         //类型为字典文件
    location    "system";           //所在目录
    object      controlDict;        //对象名
}
application     interFoam;          //求解器名称
//时间控制
startFrom       startTime;          //设置计算开始时间为startTime
startTime       0;                  //定义startTime
stopAt          endTime;            //设置计算结束时间为endTime
endTime         3;                  //定义endTime
deltaT          0.005;              //设置时间步长
//计算结果输出控制
writeControl    adjustableRunTime;  //按照计算时间控制输出
writeInterval   0.1;                //输出时间间隔,单位秒[s],与writeControl配合使用
purgeWrite      0;                  //输出是否覆盖先前记录,0为不覆盖,1可用于稳态计算,默认0
writeFormat     ascii;              //计算结果输出文件格式指定
writePrecision  10;                 //控制输出有效数字位数,与writeFormat配合使用,默认6
writeCompression uncompressed;      //是否压缩
timeFormat      general;            //时间目录名称指定
timePrecision   6;                  //时间目录名称有效数字位数,与timeFormat配合使用,默认6
//时间步长自适应控制
adjustTimeStep  yes;                //是否开启时间步长自适应
maxCo           0.5;                //最大库郎数
maxDeltaT       1.0;                //最大时间步长
//字典读取控制
runTimeModifiable yes;              //每个时间步是否读取所修改的字典文件设定

2 逐项分析

system目录下的controlDict文件用来设置 时间和输入输出控制，包括 时间控制， 计算结果输出控制，时间步长自适应控制， 字典读取控制 和 运行时加载库或者函数控制 五个部分。

2.1 application

查看$FOAM_TUTORIALS里所用到的求解器，输入命令：

foamSearch $FOAM_TUTORIALS controlDict application
//结果显示：
application     adjointShapeOptimizationFoam;
application     blockMesh;
application     boundaryFoam;
application     buoyantPimpleFoam;
application     buoyantSimpleFoam;
application     cavitatingFoam;
application     chemFoam;
application     chtMultiRegionFoam;
application     coalChemistryFoam;
application     coldEngineFoam;
application     compressibleInterFoam;
application     compressibleMultiphaseInterFoam;
application     dnsFoam;
application     DPMFoam;
application     driftFluxFoam;
application     dsmcFoam;
application     electrostaticFoam;
application     financialFoam;
application     fireFoam;
application     foamyHexMesh;
application     icoFoam;
application     icoUncoupledKinematicParcelFoam;
application     interFoam;
application     interMixingFoam;
application     interPhaseChangeFoam;
application     laplacianFoam;
application     mdEquilibrationFoam;
application     mdFoam;
application     mhdFoam;
application     moveDynamicMesh;
application     MPPICFoam;
application     multiphaseEulerFoam;
application     multiphaseInterFoam;
application     nonNewtonianIcoFoam;
application     PDRFoam;
application     pimpleFoam;
application     pisoFoam;
application     porousSimpleFoam;
application     potentialFoam;
application     potentialFreeSurfaceFoam;
application     reactingFoam;
application     reactingMultiphaseEulerFoam;
application     reactingParcelFoam;
application     reactingTwoPhaseEulerFoam;
application     rhoCentralFoam;
application     rhoPimpleFoam;
application     rhoPorousSimpleFoam;
application     rhoSimpleFoam;
application     scalarTransportFoam;
application     shallowWaterFoam;
application     simpleFoam;
application     simpleReactingParcelFoam;
application     snappyHexMesh;
application     solidDisplacementFoam;
application     solidEquilibriumDisplacementFoam;
application     sprayFoam;
application     SRFPimpleFoam;
application     SRFSimpleFoam;
application     twoLiquidMixingFoam;
application     twoPhaseEulerFoam;
application     XiEngineFoam;
application     XiFoam;

tutorial里基本上平时常用到的、不常用的solver都有，根据自己的研究方向选几个相关的再慢慢研究细节吧。

2.2 时间控制

2.2.1 startFrom, startTime

2.2.2 stopAt, endTime

2.2.3 deltaT

时间步长控制，有时需要控制 $Co=\frac{\delta t|U|}{\delta x}<1$ $\delta t$ 为时间步、就是这的deltaT; $|U|$ 为某网格单元内的速度矢量的模 $\delta x$ 为速度方向的网格长度。

2.3 输出控制

2.3.1 writeControl,writeInterval

2.3.2 purgeWrite

2.3.3 writeFormat,writePrecision

2.3.4 writeCompression, timeFormat, timePrecision

2.3.5 runTimeModifiable

Switch for whether dictionaries, e.g. controlDict, are re-read during a simulation at the beginning of each time step, allowing the user to modify parameters during a simulation.

2.3.6 graphFormat

2.4 时间步长自适应控制

2.5 运行时加载库或者函数控制

设置运行时需要加载的库或函数如下所示：

举个例子，incompressible/pimpleFoam/RAS/TJunction/system/controlDict中相关部分：

functions
{
    probes
    {
        // Where to load it from
        libs            ("libsampling.so");

        type            probes;

        // Name of the directory for probe data
        name            probes;

        // Write at same frequency as fields
        writeControl    writeTime;
        writeInterval   1;

        // Fields to be probed
        fields          (p U);

        probeLocations
        (
            ( 1e-06 0 0.01 )        // at inlet
            (0.21 -0.20999 0.01)  // at outlet1
            (0.21 0.20999 0.01)   // at outlet2
            (0.21 0 0.01)         // at central block
        );
    }
}

下面介绍最常用的probes和singleGraph函数的使用方法。

2.5.1 probes函数

该函数功能为程序运行时监测:q指定坐标点场数据随时间的变化。首先在controlDict文件内添加以下语句，调用probes功能的相关函数。

functions 
 { 
   #includeFunc probes   // 在functions列表中添加probes函数
 }

接着运行以下命令，复制probes文件至system文件夹下，

cp -r $FOAM_ETC/caseDicts/postProcessing/probes/probes system

probes文件的内容如下，

通过修改fields参数中可添加需监测的场，修改probeLocations的坐标值可添加监测点的坐标值。运行求解器后，指定坐标点的监测场随时间变化的数据输出至postProcessing/probes/0文件夹。

2.5.2 singleGraph函数

该函数功能为对计算结果数据取样并可视化。首先在controlDict文件内的functions列表中添加singleGraph函数，接着运行以下命令，复制singleGraph文件至system文件夹，

cp -r $FOAM_ETC/caseDicts/postProcessing/graphs/singleGraph system

singleGraph文件的内容如下，

 start  (0.01 0.025 0);  // 取样的起始点坐标
  end   (0.01 -0.025 0);  // 取样的终点坐标
  fields (U p);   // 取样场的名称

  // Sampling and I/O settings 
  #includeEtc ”caseDicts/postProcessing/graphs/sampleDict.cfg” 

  // Override settings here, e.g. 
  // setConfig { type midPoint; } 

  // Must be last entry 
  #includeEtc ”caseDicts/postProcessing/graphs/graph.cfg” 

修改fields参数中可添加需采样的场，修改start 和end参数可设置取样点的坐标范围。计算完成后，在算例文件夹下输入命令postProcess -func singleGraph，可对数据取样并输出至postProcessing/singleGraph文件夹。输出数据文件可直接通过gnuplot软件（需预先安装）处理实现可视化。

2.5.3 foreCoeffs

翼型模拟时常需要得到 $C_{p},C_{L},C_{D}$ 等数据，可以利用OpenFOAM的相关工具，推荐在controlDict里直接include然后在system文件夹里重新写一个文件。

//controlDict里加入
functions 
{
    #include "forceCoeffs"
};

新文件内容如下：

//文件名forceCoeffs
/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  dev
     \\/     M anipulation  |
-------------------------------------------------------------------------------
Description
    Calculates lift, drag and moment coefficients by summing forces on
    specified patches for a case where the solver is incompressible (pressure
    is kinematic, e.g. m^2/s^2).

\*---------------------------------------------------------------------------*/

forceCoeffs
{
    // Mandatory entries
    type            forceCoeffs;
    libs            ("libforces.so");
    patches         (airfoil-l1 airfoil-l2 airfoil-h1 airfoil-h2);


    // Optional entries

    // Field names
    p               p;
    U               U;
    rho     rhoInf;
    log         true;
    rhoInf      1.225;
    // Reference pressure [Pa]
    pRef            0;

    // Include porosity effects?
    porosity        yes;

    // Store and write volume field representations of forces and moments
    writeFields     yes;

    // Centre of rotation for moment calculations
    CofR            (0.25 0 0);

    // Lift direction
    liftDir         (0 1 0);

    // Drag direction
    dragDir         (1 0 0);

    // Pitch axis
    pitchAxis       (0 0 1);

    // Freestream velocity magnitude [m/s]
    magUInf         50;

    // Reference length [m]
    lRef            1;

    // Reference area [m2]
    Aref            1.2;

    // Spatial data binning
    // - extents given by the bounds of the input geometry
    binData
    {
        nBin        21;
        direction   (1 0 0);
        cumulative  yes;
    }
}

具体内容可参考OpenFOAM在线文档。