rhoCentralFoam求解器的问题



  • 最近在看rhoCentralFoam求解器,有一些问题,请教各位:
    在使用openfoam中rhoCentralFoam求解器时,我参照其中的例子结合自身算例,给定了边界条件及初始值,在计算4000步后,出现如下错误:

    --> FOAM FATAL ERROR: 
    Maximum number of iterations exceeded
    
        From function Foam::scalar Foam::species::thermo<Thermo, Type>::T(Foam::scalar, Foam::scalar, Foam::scalar, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar, Foam::scalar) const, Foam::scalar (Foam::species::thermo<Thermo, Type>::*)(Foam::scalar) const) const [with Thermo = Foam::hConstThermo<Foam::perfectGas<Foam::specie> >; Type = Foam::sensibleInternalEnergy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>]
        in file /home/liyue/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66.
    
    FOAM aborting
    
    #0  Foam::error::printStack(Foam::Ostream&) at ~/OpenFOAM/OpenFOAM-3.0.1/src/OSspecific/POSIX/printStack.C:218
    #1  Foam::error::abort() at ~/OpenFOAM/OpenFOAM-3.0.1/src/OpenFOAM/lnInclude/error.C:249
    #2  Foam::Ostream& Foam::operator<< <Foam::error>(Foam::Ostream&, Foam::errorManip<Foam::error>) at ~/OpenFOAM/OpenFOAM-3.0.1/src/OpenFOAM/lnInclude/errorManip.H:85 (discriminator 4)
    #3  Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::T(double, double, double, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double, double) const, double (Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::*)(double) const) const at ~/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/specie/lnInclude/thermoI.H:66
    #4  Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::TEs(double, double, double) const at ~/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/specie/lnInclude/thermoI.H:425
    #5  Foam::sensibleInternalEnergy<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> >::THE(Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> const&, double, double, double) const at ~/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/specie/lnInclude/sensibleInternalEnergy.H:126
    #6  Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy>::THE(double, double, double) const at ~/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/specie/lnInclude/thermoI.H:365
    #7  Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::calculate() at ~/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/basic/psiThermo/hePsiThermo.C:46 (discriminator 2)
    #8  Foam::hePsiThermo<Foam::psiThermo, Foam::pureMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleInternalEnergy> > > >::correct() at ~/OpenFOAM/OpenFOAM-3.0.1/src/thermophysicalModels/basic/psiThermo/hePsiThermo.C:143
    #9  ? at ~/OpenFOAM/OpenFOAM-3.0.1/applications/solvers/compressible/rhoCentralFoam/rhoCentralFoam.C:232
    #10  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
    #11  ? at ??:?
    Aborted (core dumped)
    

    结合前面求解e方程残差无变化,我分析,这是由于e的求解修正出现了错误,为查找错误来源,我想在rhoCentralFoam的求解器中加断点,看求解过程中的数值传递与变化。

    于是,我采用了debug模式在rhoCentralFoam.C的215行加入断点,想输出e,结果屏幕输出了大量信息,我应该如何输出才能得到想要的场信息呢

    1. 如果我想梳理出程序运行的主线,搞清楚从场的离散点到通过离散方法,获得最终求解的代数方程矩阵,我认为最好的办法是从建立场开始,关注场中存储的离散点的信息变化。那么请问如何输出存储点压力,面通量信息的矩阵呢?


  • @vivian
    错误显示迭代步数超出了。

    我采用了debug模式在rhoCentralFoam.C的215行加入断点,想输出e,结果屏幕输出了大量信息,我应该如何输出才能得到想要的场信息呢?

    e是个场,你要输出场的话,就会输出所有的场的值,不清楚你要看什么,也可以单独输出场的最大值最小值看看越界否。如果一定要查看整个场的信息,输出到log再看,这样log文件会变得很大。

    rhoCentralFoam &> log

    如果我想梳理出程序运行的主线,搞清楚从场的离散点到通过离散方法,获得最终求解的代数方程矩阵,我认为最好的办法是从建立场开始,关注场中存储的离散点的信息变化。那么请问如何输出存储点压力,面通量信息的矩阵呢?

    从离散的矩阵系数如fvScalarMatrix组建我们常规的稀疏矩阵不是一俩行代码可以搞定(估计不到100行?)因为openfoam里面存储的是稀疏矩阵,并用指针+指针。所以,可能得用点时间。

    更简单的方法,是回到问题本身,很少是因为矩阵系统解不出来的原因,而是设置有问题导致发散。



  • @cfd-china 厉害了我的哥



  • 谢谢您的回复!:big_mouth:
    结合tutorial中wedge15的算例,我的模拟模型为马赫数2的压缩拐角流动。入口设置了速度边界,出口为超声速出口。采用k-epsilon湍流模型,所需k,epsilon值根据经验公式给出。

    压力场设定为:

    internalField   uniform 100000;
    
    boundaryField
    {
        INLET
        
        {
            type            inletOutlet;
            inletValue      uniform 101325;
            value           uniform 101325;
        }
        
    
        OUTLET
        {
            type            waveTransmissive;
            field           p;
            phi             phi;
            rho             rho;
            psi             thermo:psi;
            gamma           1.3;
            fieldInf        100000;
            lInf            1;
            value           uniform 100000;
        }
    
        BOTTOM
        {
            type            zeroGradient;
    
        }
        TOP
        {
            type            zeroGradient;
        }
        frontAndBackPlanes
        {
            type            empty;
            
        }    
    }
    

    速度设定为:

    dimensions      [0 1 -1 0 0 0 0];
    
    internalField   uniform (600 0 0);
    
    boundaryField
    {
        INLET
        {
            type            supersonicFreestream;
            pInf            100000;
            TInf            300;
            UInf            (600 0 0);
            gamma           1.4;
            value           uniform (662 0 0);
        }
    
        OUTLET
        {
            type            inletOutlet;
            inletValue      uniform (662 0 0);
            value           uniform (662 0 0);
        }
    
        BOTTOM
        {
            type            zeroGradient;
    
        }
        TOP
        {
            type            symmetryPlane;
        }
        frontAndBackPlanes
        {
            type            empty;
            
        } 
        
    }
    

    温度场设置为:

    internalField   uniform 300;
    
    boundaryField
    {
        INLET
        {
            type            inletOutlet;
            inletValue      uniform 300;
            value           uniform 300;
        }
    
        OUTLET
        {
            type            inletOutlet;
            inletValue      uniform 300;
            value           uniform 300;
        }
    
        BOTTOM
        {
            type            zeroGradient;
    
        }
        TOP
        {
            type            symmetryPlane;
        }
        frontAndBackPlanes
        {
            type            empty;
            
        } 
    

    求解器的设置是根据相似算例给出,这个的设置有什么原则吗?我设置的如下,还请多多指点:

    solvers
    {
        "rho.*"
        {
            solver          diagonal;
        }
    
        "p.*"
        {
            solver          PBiCG;
            preconditioner  DILU;
            tolerance       1e-12;
            relTol          0;
        }
    
        "(U|e).*"
        {
            $p;
            tolerance       1e-9;
        }
    
        "(nuTilda).*"
        {
            $p;
            tolerance       1e-10;
        }
    }
    
    PIMPLE
    {
        nOuterCorrectors 1;
        nCorrectors      2;
        nNonOrthogonalCorrectors 0;
    }
    

    Q1:不知道我这样设置边界条件是否合理哪?
    Q2:求解器的选择应该如何设置呢,有什么选择原则,请问有什么资料推荐码?
    Q3:在外部参数设置找不出差错,又有发散产生时,请问如何debug呢?


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