网格流动性优化求助

OpenFOAM
1

我的模型是y型通道。但是气体在刚刚通入管道之后就发散了，老师说是网格流动性有问题，可是这方面应该怎么改，下面是我的相关文件，求各位老师指点。
这是p文件和u文件以及时间步长文件

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    location    "0";
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [ 1 -1 -2 0 0 0 0 ];

internalField   uniform 101325;

boundaryField
{
    fuel
    {
       type            fixedValue;
       value           uniform 101325;
    }
    air
    {
       type            fixedValue;
       value           uniform 101325;
    }
    outlet
    {
        type            fixedValue;
        value           uniform 101325;
    }
    front
    {
        type            empty;
    }
    back
    {
        type            empty;
    }
    lowwall
    {
        type            zeroGradient;
        value           uniform 0;
    }
    upwall
    {
        type            zeroGradient;
        value           uniform 0;
    }
   otherwall
   {
       type            zeroGradient;
       value           uniform 0;
   }
}

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    location    "0";
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [ 0 1 -1 0 0 0 0 ];

internalField   uniform ( 4 0 0 );

boundaryField
{
    fuel
    {
        type            fixedValue;
        value           uniform ( 0.25 -0.25 0 );
    }
     air
    {
      type              fixedValue;
        value           uniform ( 0.25  0.25 0 );
     }
    outlet
    {
        type            zeroGradient;
    }
    front
    {
        type            empty;
    }
    back
    {
        type            empty;
    }
    otherwall
     {
        type            fixedValue;
        value           uniform ( 0 0 0 );
    }
    lowwall
    {
        type            fixedValue;
        value           uniform ( 0 0 0 );
    }
    upwall
    {
        type            fixedValue;
        value           uniform ( 0 0 0 );
    }
}

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.4.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     MDreactingLMFoam;

startFrom       latestTime;

startTime       0;

stopAt          endTime;

endTime         0.05;

deltaT          1e-4;

writeControl    adjustableRunTime;

writeInterval   1e-4;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;

adjustTimeStep  yes;

maxCo           0.1;
2

这个应该是边界的设置问题吧？

一般来说，压力和速度只能指定其中一个为 fixedValue ，另一个为 zeroGradient，而且不能所有速度都为 fixedValue。所以，你试试，把 fuel 和 air 的压力都设为 zeroGradient.

网格流动性？没怎么听过这个说法呢？

3

感谢老师的回复，我的算例出现的问题是网格检查没问题，但是却出现了发散，老师让我检查气体在网格中的流动性，之前表述上有些问题