jet 的边界条件如何选择?



  • 各位大佬,请问谁有经验处理过类似jet的boundary condition?
    下图是使用incompressible solver后达到steady-state的速度场,现在因为其他原因,要使用comprenssible solver,但是使用相同的边界条件会导致计算发散。
    54e8805d-701e-46a9-a1ac-97c8a281723c-image.png

    目前的compressible solver 的边界条件如下

    
    inlet
     { 特定profile
        }
        outlet
        {
            /*type            pressureInletOutletVelocity;
            value           uniform (0 0 0);
            inletValue      uniform (0 0 0);*/
    		type 			inletOutlet;
    		phi 			phi;
    		inletValue 		$internalField;
    		value 			$internalField;
        }
        walls
        {
            type                noSlip;
        }
    
    }
    
    压力场
    internalField       uniform 1e+05;
    
    
    
    boundaryField
    {
        inlet
        {
           		type			totalPressure;
    		p0				$internalField;
        }
        outlet
        {
           		type			zeroGradient;
    		 
        }
        walls
        {
            type            zeroGradient;
        }
    
    }
    
    k
    
    dimensions      [0 2 -2 0 0 0 0];
    
    internalField   uniform 0.1;
    
    
    boundaryField
    {
        inlet
        {
            type turbulentIntensityKineticEnergyInlet;
    		intensity 0.145;
    		value $internalField; // placeholder
        }
        walls
        {
            
    		type            kqRWallFunction;
            value           uniform 1;
        }
        outlet
        {
            type            inletOutlet;
            inletValue      uniform 0;
            value           uniform 0;
        }
    
    }
    
    
    epsilon
    
    boundaryField
    {
        inlet
        {
            type            turbulentMixingLengthDissipationRateInlet;
            mixingLength    2.0e-5;
            value           $internalField;
        }
        walls
        {
    
    		 type            zeroGradient;
           
        }
        outlet
        {
            type            inletOutlet;
            inletValue      $internalField;
            value           $internalField;
        }
    
    }
    

    如果哪位大佬有相关经验,麻烦指点一下。谢谢



  • 速度不是很高,但是gradient很大,速度的峰值在12m/s 左右,gradient在整个diameter 10% 左右就变为0了。
    网格也不是很复杂,是一个圆柱,中间有加密的ogrid


  • OpenFOAM讲师

    老问题,我也遇到过几次,我是压力速度耦合部分发散,试过如下修改,压力出口用无反射边界条件(可压缩),使用湍流模型时时间步长减小,直接喷管出口的速度入口可以试一下1/7次方速度分布而不是均匀速度进入



  • @yfclark
    麻烦介绍一下哪个是无反射边界条件?
    速度入口我没法修改的,是实验数据


  • OpenFOAM讲师

    waveTransmissive,我说的速度是考虑出口边界层对速度在空间上分布的影响,如果实验测的分布很真实,不需要考虑这个



  • @yfclark

    谢谢 我试试,刚才刚又试错了一下,看看修改以后如何

    Courant Number mean: 0.0011211 max: 0.20004
    Time = 0.0089
    
    
    Solving 3-D cloud sprayCloud
    Cloud: sprayCloud
       Current number of parcels       = 0
       Current mass in system          = 0
       Linear momentum                 = (0 0 0)
      |Linear momentum|                = 0
       Linear kinetic energy           = 0
       model1:
           number of parcels added     = 0
           mass introduced             = 0
       model2:
           number of parcels added     = 0
           mass introduced             = 0
       model3:
           number of parcels added     = 0
           mass introduced             = 0
       model4:
           number of parcels added     = 0
           mass introduced             = 0
       model5:
           number of parcels added     = 0
           mass introduced             = 0
       model6:
           number of parcels added     = 0
           mass introduced             = 0
       model7:
           number of parcels added     = 0
           mass introduced             = 0
       model8:
           number of parcels added     = 0
           mass introduced             = 0
       model9:
           number of parcels added     = 0
           mass introduced             = 0
       model10:
           number of parcels added     = 0
           mass introduced             = 0
       model11:
           number of parcels added     = 0
           mass introduced             = 0
       model12:
           number of parcels added     = 0
           mass introduced             = 0
       model13:
           number of parcels added     = 0
           mass introduced             = 0
       model14:
           number of parcels added     = 0
           mass introduced             = 0
       model15:
           number of parcels added     = 0
           mass introduced             = 0
       model16:
           number of parcels added     = 0
           mass introduced             = 0
       model17:
           number of parcels added     = 0
           mass introduced             = 0
       model18:
           number of parcels added     = 0
           mass introduced             = 0
       model19:
           number of parcels added     = 0
           mass introduced             = 0
       model20:
           number of parcels added     = 0
           mass introduced             = 0
       model21:
           number of parcels added     = 0
           mass introduced             = 0
       model22:
           number of parcels added     = 0
           mass introduced             = 0
       model23:
           number of parcels added     = 0
           mass introduced             = 0
       model24:
           number of parcels added     = 0
           mass introduced             = 0
       model25:
           number of parcels added     = 0
           mass introduced             = 0
       model26:
           number of parcels added     = 0
           mass introduced             = 0
       model27:
           number of parcels added     = 0
           mass introduced             = 0
       model28:
           number of parcels added     = 0
           mass introduced             = 0
       model29:
           number of parcels added     = 0
           mass introduced             = 0
       model30:
           number of parcels added     = 0
           mass introduced             = 0
       model31:
           number of parcels added     = 0
           mass introduced             = 0
       Parcel fate (number, mass)      : patch inlet
         - escape                      = 0, 0
         - stick                       = 0, 0
       Parcel fate (number, mass)      : patch walls
         - escape                      = 0, 0
         - stick                       = 0, 0
       Parcel fate (number, mass)      : patch outlet
         - escape                      = 0, 0
         - stick                       = 0, 0
       Temperature min/max             = 0, 0
       Mass transfer phase change      = 0
       D10, D32, Dmax (mu)             = 0, 0, 0
       Liquid penetration 95% mass (m) = 0
    
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    PIMPLE: iteration 1
    GAMG:  Solving for Ux, Initial residual = 0.0037785, Final residual = 9.6735e-10, No Iterations 2
    GAMG:  Solving for Uy, Initial residual = 0.0037745, Final residual = 1.0196e-09, No Iterations 2
    GAMG:  Solving for Uz, Initial residual = 0.0052513, Final residual = 7.2493e-09, No Iterations 1
    DILUPBiCG:  Solving for H2O:  solution singularity
    DILUPBiCG:  Solving for h, Initial residual = 0.0041966, Final residual = 1.7553e-06, No Iterations 1
    T gas min/max   = 297.98, 298.06
    GAMG:  Solving for p, Initial residual = 0.0040789, Final residual = 8.4078e-08, No Iterations 17
    GAMG:  Solving for p, Initial residual = 8.4041e-08, Final residual = 6.0506e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 6.273e-11, global = -3.4834e-11, cumulative = -9.0638e-09
    rho max/min : 1.1693 1.1679
    GAMG:  Solving for p, Initial residual = 1.8592e-05, Final residual = 6.078e-08, No Iterations 5
    GAMG:  Solving for p, Initial residual = 6.078e-08, Final residual = 3.4733e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 3.601e-11, global = -6.4427e-12, cumulative = -9.0703e-09
    rho max/min : 1.1693 1.1679
    GAMG:  Solving for p, Initial residual = 7.8717e-07, Final residual = 5.5203e-08, No Iterations 2
    GAMG:  Solving for p, Initial residual = 5.5203e-08, Final residual = 3.6842e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 3.8197e-11, global = 2.3727e-12, cumulative = -9.0679e-09
    rho max/min : 1.1693 1.1679
    GAMG:  Solving for epsilon, Initial residual = 1, Final residual = 7.3363e-15, No Iterations 1
    bounding epsilon, min: -1.0372 max: 71109 average: 1.3751
    GAMG:  Solving for k, Initial residual = 0.01149, Final residual = 1.4722e-09, No Iterations 2
    bounding k, min: -0.0028333 max: 4.2155 average: 0.095222
    PIMPLE: iteration 2
    GAMG:  Solving for Ux, Initial residual = 0.82941, Final residual = 1.8962e-11, No Iterations 1
    GAMG:  Solving for Uy, Initial residual = 0.78244, Final residual = 3.1846e-10, No Iterations 1
    GAMG:  Solving for Uz, Initial residual = 0.77963, Final residual = 3.396e-10, No Iterations 1
    DILUPBiCG:  Solving for H2O:  solution singularity
    DILUPBiCG:  Solving for h, Initial residual = 0.99986, Final residual = 1.0717e-09, No Iterations 2
    T gas min/max   = 297.98, 298.06
    GAMG:  Solving for p, Initial residual = 0.00018278, Final residual = 7.4859e-08, No Iterations 16
    GAMG:  Solving for p, Initial residual = 7.4848e-08, Final residual = 5.6773e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 5.8874e-11, global = -4.1007e-11, cumulative = -9.1089e-09
    rho max/min : 1.2053 1.1679
    GAMG:  Solving for p, Initial residual = 1.5556e-05, Final residual = 6.5459e-08, No Iterations 7
    GAMG:  Solving for p, Initial residual = 6.5459e-08, Final residual = 6.1625e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 6.3906e-11, global = 2.1691e-11, cumulative = -9.0872e-09
    rho max/min : 1.2058 1.1679
    GAMG:  Solving for p, Initial residual = 1.1122e-06, Final residual = 8.7402e-08, No Iterations 3
    GAMG:  Solving for p, Initial residual = 8.7402e-08, Final residual = 5.5515e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 5.757e-11, global = 7.2634e-12, cumulative = -9.08e-09
    rho max/min : 1.2058 1.1679
    GAMG:  Solving for epsilon, Initial residual = 0.99999, Final residual = 4.4529e-10, No Iterations 1
    bounding epsilon, min: -23.934 max: 71109 average: 1.3766
    GAMG:  Solving for k, Initial residual = 0.99999, Final residual = 4.4898e-08, No Iterations 70
    bounding k, min: -2.2943e+07 max: 3.6509e+08 average: 3191.4
    PIMPLE: iteration 3
    GAMG:  Solving for Ux, Initial residual = 0.72148, Final residual = 2.8168e-08, No Iterations 8
    GAMG:  Solving for Uy, Initial residual = 0.92796, Final residual = 4.6542e-08, No Iterations 8
    GAMG:  Solving for Uz, Initial residual = 0.96434, Final residual = 7.2671e-08, No Iterations 8
    DILUPBiCG:  Solving for H2O:  solution singularity
    DILUPBiCG:  Solving for h, Initial residual = 1, Final residual = 0.023093, No Iterations 2
    T gas min/max   = 297.98, 298.06
    GAMG:  Solving for p, Initial residual = 0.0080768, Final residual = 7.9938e-08, No Iterations 28
    GAMG:  Solving for p, Initial residual = 7.9316e-08, Final residual = 5.7723e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 6.0768e-11, global = -4.0651e-11, cumulative = -9.1206e-09
    rho max/min : 1.848 0.96985
    GAMG:  Solving for p, Initial residual = 0.0019589, Final residual = 7.5856e-08, No Iterations 21
    GAMG:  Solving for p, Initial residual = 7.5892e-08, Final residual = 5.1389e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 5.4049e-11, global = -3.7593e-11, cumulative = -9.1582e-09
    rho max/min : 1.7398 0.94843
    GAMG:  Solving for p, Initial residual = 0.00036546, Final residual = 7.76e-08, No Iterations 23
    GAMG:  Solving for p, Initial residual = 7.7608e-08, Final residual = 5.611e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 5.9e-11, global = -4.0674e-11, cumulative = -9.1989e-09
    rho max/min : 1.878 0.98689
    GAMG:  Solving for epsilon, Initial residual = 1, Final residual = 4.5124e-08, No Iterations 9
    bounding epsilon, min: -2.6567e+14 max: 9.8944e+14 average: 4.3069e+11
    GAMG:  Solving for k, Initial residual = 3.1203e-05, Final residual = 3.4191e-08, No Iterations 3
    bounding k, min: -0.0028429 max: 1.1084e+08 average: 13164
    PIMPLE: iteration 4
    GAMG:  Solving for Ux, Initial residual = 0.69715, Final residual = 8.8458e-13, No Iterations 1
    GAMG:  Solving for Uy, Initial residual = 0.66265, Final residual = 5.0469e-13, No Iterations 1
    GAMG:  Solving for Uz, Initial residual = 0.89007, Final residual = 1.8401e-13, No Iterations 1
    DILUPBiCG:  Solving for H2O:  solution singularity
    DILUPBiCG:  Solving for h, Initial residual = 0.93521, Final residual = 0.060826, No Iterations 1
    T gas min/max   = -28.694, 299.97
    GAMG:  Solving for p, Initial residual = 0.17195, Final residual = 7.8752e-08, No Iterations 29
    GAMG:  Solving for p, Initial residual = 8.8696e-08, Final residual = 6.5726e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 7.5836e-11, global = 5.0269e-11, cumulative = -9.1486e-09
    rho max/min : 1.4518 0
    GAMG:  Solving for p, Initial residual = 0.05066, Final residual = 9.9767e-08, No Iterations 26
    GAMG:  Solving for p, Initial residual = 1.027e-07, Final residual = 7.4687e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 8.1351e-11, global = -5.5958e-11, cumulative = -9.2046e-09
    rho max/min : 1.3965 0
    GAMG:  Solving for p, Initial residual = 0.016961, Final residual = 8.0106e-08, No Iterations 23
    GAMG:  Solving for p, Initial residual = 8.0702e-08, Final residual = 5.627e-08, No Iterations 1
    diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
    time step continuity errors : sum local = 6.0392e-11, global = 4.4356e-11, cumulative = -9.1602e-09
    rho max/min : 1.3959 0
    GAMG:  Solving for epsilon, Initial residual = 1, Final residual = 6.2629e-16, No Iterations 1
    bounding epsilon, min: -2.2666e+12 max: 4.6152e+10 average: -2.4192e+07
    GAMG:  Solving for k, Initial residual = 0.99984, Final residual = 1.5475e-11, No Iterations 1
    bounding k, min: -2.7051e+07 max: 5.1083e+07 average: 6384.9
    PIMPLE: iteration 5
    GAMG:  Solving for Ux, Initial residual = 0.88859, Final residual = 1.3661e-07, No Iterations 1000
    GAMG:  Solving for Uy, Initial residual = 0.9647, Final residual = 9.9942e-08, No Iterations 598
    GAMG:  Solving for Uz, Initial residual = 0.90627, Final residual = 4.0161e-06, No Iterations 1000
    DILUPBiCG:  Solving for H2O:  solution singularity
    DILUPBiCG:  Solving for h, Initial residual = 1, Final residual = 0.024346, No Iterations 2
    [7] 
    [7] 
    [7] --> FOAM FATAL ERROR: 
    [7] Maximum number of iterations exceeded
    [7] 
    [7]     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::sensibleEnthalpy; Foam::scalar = double; Foam::species::thermo<Thermo, Type> = Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>]
    [7]     in file /export/opt/openfoam/OpenFOAM-4.1/src/thermophysicalModels/specie/lnInclude/thermoI.H at line 66.
    [7] 
    FOAM parallel run aborting
    [7] 
    [7] #0  Foam::error::printStack(Foam::Ostream&) at ??:?
    [7] #1  Foam::error::abort() at ??:?
    [7] #2  Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy>::THs(double, double, double) const at ??:?
    [7] #3  Foam::hePsiThermo<Foam::psiReactionThermo, Foam::SpecieMixture<Foam::reactingMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > > >::calculate() at ??:?
    [7] #4  Foam::hePsiThermo<Foam::psiReactionThermo, Foam::SpecieMixture<Foam::reactingMixture<Foam::constTransport<Foam::species::thermo<Foam::hConstThermo<Foam::perfectGas<Foam::specie> >, Foam::sensibleEnthalpy> > > > >::correct() at ??:?
    [7] #5  ? at ??:?
    [7] #6  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
    [7] #7  ?--------------------------------------------------------------------------
    MPI_ABORT was invoked on rank 7 in communicator MPI_COMM_WORLD 
    with errorcode 1.
    
    NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
    You may or may not see output from other processes, depending on
    exactly when Open MPI kills them.
    --------------------------------------------------------------------------
    at ??:?
    
    ^C
    
    

  • OpenFOAM讲师

    好像是湍流先发散啊,然后是温度



  • @yfclark 是的,而且我用的PIMPLE,一直连内循环都不收敛 很头大



  • @星星星星晴jet 的边界条件如何选择? 中说:

    inlet
    { 特定profile

    想请问一下你这里入口的特定profile是怎么实现的呀?



  • @hotairballon1997 先输出cell的坐标,然后根据你的实验数据,或者你profile拟合出来的方程给每个cell一个vector。我之前有个帖子写了方法的





  • @星星星星晴 非常感谢,确实有用,就相当于手动map了一下入口场



  • @hotairballon1997 算吧 不过不是map,我个人觉得不要轻易用map这个人东西。。因为网格密度不同,map出来的场可能是有问题的


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