Continuity error该给什么样的边界条件呀？

[东方白杨]

我把边界条件都改了一遍，还是有这个问题，做的是一个通道流动，用的是buoyantBoussinesqSimpleFoam，给了进口速度1.82m/s，出口大气压，流体温度20K，壁面300K，边界条件如下：
速度：

FoamFile
{
    version     2.0;
    format      ascii;
    class       volVectorField;
    object      U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform (1.82 0 0);

boundaryField
{
    inlet
    {
        type            fixedValue;
        value           uniform (1.82 0 0);
    }

    outlet
    {
        type            zeroGradient;
    }

    top
    {
        type            noSlip;
    }

    ground
    {
        type            noSlip;
    }

    FrontandBack
    {
        type            noSlip;
    }

    Trib
    {
        type            noSlip;
    }
}

压力：

boundaryField
{
    inlet
    {
        type            zeroGradient;
    }

    outlet
    {
        type            fixedValue;
        value           uniform 0;//大气压出口
    }

    top
    {
        type            zeroGradient;
    }

    ground
    {
        type            zeroGradient;
    }

    FrontandBack
    {
        type            zeroGradient;
    }

    Trib
    {
        type            zeroGradient;
    }
}

参考压力：

FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform 0;

boundaryField
{   
    "(inlet|outlet|top|ground|FrontandBack|Trib)"
    {
        type            fixedFluxPressure;
        value           $internalField;
    }
}

一直报错如下：

--> FOAM FATAL ERROR:
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux              : 0.999375
Specified mass inflow   : 0.0167107
Specified mass outflow  : 0
Adjustable mass outflow : 0


    From function bool Foam::adjustPhi(Foam::surfaceScalarField&, const volVectorField&, Foam::volScalarField&)
    in file cfdTools/general/adjustPhi/adjustPhi.C at line 111.

FOAM exiting