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@李东岳感谢李老师回复指导

因为之前是基于多种设置续算的，就从0开始重新算了一下。可能是振动还没发展起来或者别的原因，现在还没有复现出问题1，问题2的情况也有所缓解。

因为要算的工况比较多，每工况的模拟时间也比较长，所以才用了PIMPLE，后续会和PISO对比一下。谢谢李老师的建议！

log如下：

PIMPLE: iteration 1
forces forces:
    rho: rhoInf
    Freestream density (rhoInf) set to 1024.81
    Not including porosity effects

Restraint verticalSpring:  attachmentPt - anchor (0 0.0010966357 0) spring length 0.0010966357 force (0 -0.10118346 0)
6-DoF rigid body motion
    Centre of rotation: (0 0.0010691972 0.15)
    Centre of mass: (0 0.0010691972 0.15)
    Orientation: (1 0 0 0 1 0 0 0 1)
    Linear velocity: (0 -0.01668704 0)
    Angular velocity: (0 0 0)
GAMG:  Solving for pcorr, Initial residual = 1, Final residual = 0.01988723, No Iterations 36
GAMG:  Solving for pcorr, Initial residual = 0.15492815, Final residual = 0.019874775, No Iterations 3
time step continuity errors : sum local = 3.7598085e-09, global = 3.4248906e-10, cumulative = -6.3316969e-09
smoothSolver:  Solving for Ux, Initial residual = 0.00014400004, Final residual = 2.2329647e-06, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.0020709532, Final residual = 3.1958459e-05, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00066233531, Final residual = 8.9617005e-06, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.14903872, Final residual = 0.0013876837, No Iterations 5
GAMG:  Solving for p, Initial residual = 0.0049832553, Final residual = 4.6426996e-05, No Iterations 32
time step continuity errors : sum local = 7.443206e-10, global = 5.6565011e-11, cumulative = -6.2751319e-09
GAMG:  Solving for p, Initial residual = 0.080233525, Final residual = 0.00073683149, No Iterations 5
GAMG:  Solving for p, Initial residual = 0.0027394104, Final residual = 9.8256671e-08, No Iterations 197
time step continuity errors : sum local = 1.6053351e-12, global = 1.4372461e-13, cumulative = -6.2749881e-09
PIMPLE: iteration 2
smoothSolver:  Solving for Ux, Initial residual = 5.2998192e-05, Final residual = 9.0530989e-07, No Iterations 1
smoothSolver:  Solving for Uy, Initial residual = 0.00075801305, Final residual = 1.2921938e-05, No Iterations 1
smoothSolver:  Solving for Uz, Initial residual = 0.00023451882, Final residual = 3.4634273e-06, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.071265773, Final residual = 0.00051097706, No Iterations 5
GAMG:  Solving for p, Initial residual = 0.0021031081, Final residual = 1.9347582e-05, No Iterations 30
time step continuity errors : sum local = 3.1370341e-10, global = 2.5263834e-11, cumulative = -6.2497243e-09
GAMG:  Solving for p, Initial residual = 0.040103047, Final residual = 0.00026070028, No Iterations 5
GAMG:  Solving for p, Initial residual = 0.0011598975, Final residual = 9.7230208e-08, No Iterations 150
time step continuity errors : sum local = 1.5923563e-12, global = 1.2733625e-13, cumulative = -6.249597e-09
PIMPLE: iteration 3


PIMPLE: iteration 4


PIMPLE: iteration 5


PIMPLE: iteration 6


PIMPLE: iteration 7


PIMPLE: iteration 8


PIMPLE: iteration 9


PIMPLE: iteration 10
smoothSolver:  Solving for Ux, Initial residual = 5.8890765e-08, Final residual = 5.8890765e-08, No Iterations 0
smoothSolver:  Solving for Uy, Initial residual = 5.8962683e-07, Final residual = 5.8962683e-07, No Iterations 0
smoothSolver:  Solving for Uz, Initial residual = 1.8452167e-07, Final residual = 1.8452167e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 0.0005765656, Final residual = 5.0530797e-06, No Iterations 4
GAMG:  Solving for p, Initial residual = 1.3481753e-05, Final residual = 1.2684884e-07, No Iterations 34
time step continuity errors : sum local = 2.0757314e-12, global = -1.6681465e-13, cumulative = -6.290363e-09
GAMG:  Solving for p, Initial residual = 0.00035690212, Final residual = 2.8143682e-06, No Iterations 4
GAMG:  Solving for p, Initial residual = 7.8004164e-06, Final residual = 9.4688323e-08, No Iterations 32
time step continuity errors : sum local = 1.5495463e-12, global = -1.2432685e-13, cumulative = -6.2904873e-09
PIMPLE: iteration 11
smoothSolver:  Solving for Ux, Initial residual = 4.2089274e-08, Final residual = 4.2089274e-08, No Iterations 0
smoothSolver:  Solving for Uy, Initial residual = 4.6201943e-07, Final residual = 4.6201943e-07, No Iterations 0
smoothSolver:  Solving for Uz, Initial residual = 1.2388523e-07, Final residual = 1.2388523e-07, No Iterations 0
GAMG:  Solving for p, Initial residual = 0.11552903, Final residual = 0.0010667998, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.003825712, Final residual = 3.5873819e-05, No Iterations 27
time step continuity errors : sum local = 8.3616504e-10, global = -6.3755075e-11, cumulative = -6.3542424e-09
GAMG:  Solving for p, Initial residual = 0.032558178, Final residual = 0.00030672465, No Iterations 3
GAMG:  Solving for p, Initial residual = 0.00088095902, Final residual = 9.6112528e-08, No Iterations 154
time step continuity errors : sum local = 2.1285461e-12, global = -1.790588e-13, cumulative = -6.3544214e-09
smoothSolver:  Solving for omega, Initial residual = 3.6974157e-06, Final residual = 1.8111492e-07, No Iterations 1
smoothSolver:  Solving for k, Initial residual = 0.00057213364, Final residual = 1.4744873e-07, No Iterations 3
bounding k, min: -6.9207899e-06 max: 0.028407784 average: 0.0012676458
PIMPLE: converged in 11 iterations
ExecutionTime = 4850.49 s  ClockTime = 4876 s

--> FOAM Warning : 
    From Foam::IOobjectList Foam::sampledSurfaces::preCheckFields()
    in file sampledSurface/sampledSurfaces/sampledSurfaces.C at line 138
    
Cannot find registered field matching 1(Q)
forces forces write:
    Sum of forces
        Total    : (0.93724138 0.021367463 -0.070174322)
        Pressure : (0.91719323 0.019209612 -0.066963711)
        Viscous  : (0.020048151 0.0021578513 -0.0032106112)
    Sum of moments
        Total    : (-0.0069183905 0.16084472 -0.00098339753)
        Pressure : (-0.0064798603 0.15767397 -0.00097408967)
        Viscous  : (-0.00043853028 0.0031707533 -9.3078582e-06)
    writing force and moment files.

Courant Number mean: 0.08151294 max: 4.9972435
deltaT = 0.0016751103
Time = 0.45223894

CHRISVC

假如约束太弱的话，就是会漂出去一段距离，也和实际情况相符。可以提高约束刚度试试。

CHRISVC

通过网上各种教程攒出来一个用sixDofRigidBodyMotion库模拟圆柱涡激振动的案例，目前能跑起来不发散，结果不算离谱，但是存在几个小问题想请教：

PIMPLE外循环次数超过100都不收敛，是residual定的太小了吗？尝试修改过tolerence和residuals，貌似没有影响。
尝试过用GAMG和PCG求解器，在每个循环内计算p都要很多次（200+）迭代才能收敛，这个正常吗？看教程说一般20次以内就收敛了，是应该提高nCorrectors么？
对于流固耦合模拟，想请教PIMPLE下面的residual control和上面的tolerance取值标准是啥？
从精度和计算效率两方面可以如何优化呢？

fvSchemes

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2306                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         CrankNicolson 0;
}

gradSchemes
{
    default         cellLimited Gauss linear 1;
    grad(k)         cellLimited Gauss linear 1;
    grad(omega)     cellLimited Gauss linear 1;
    grad(U)         cellLimited Gauss linear 1;
}

divSchemes
{
    default         none;
    div(phi,U)      Gauss linearUpwind grad(U);
    div(phi,k)      Gauss linearUpwind grad(k);
    div(phi,omega)  Gauss linearUpwind grad(omega);
    div((nuEff*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear limited 1;
}

snGradSchemes
{
    default         limited 1;
}

interpolationSchemes
{
    default         linear;
}

wallDist
{
    method          meshWave;
}


// ************************************************************************* //

fvSolution

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2306                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    "pcorr.*"
    {
        solver           GAMG;
        tolerance        0.02;
        relTol           0;
        smoother         GaussSeidel;
    }

    p
    {
        $pcorr;
        tolerance        1e-7;
        relTol           0.01;
    }

    pFinal
    {
        $p;
        tolerance        1e-7;
        relTol           0;
    }

    "(U|k|omega)"
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-06;
        relTol          0.1;
    }

    "(U|k|omega)Final"
    {
        $U;
        tolerance       1e-06;
        relTol          0;
    }

    cellDisplacement
    {
        solver          GAMG;
        tolerance       1e-7;
        relTol          0;
        smoother        GaussSeidel;
    }
}

PIMPLE
{
    correctPhi          yes;
    nOuterCorrectors    50;
    nCorrectors         2;
    nNonOrthogonalCorrectors 1;

    residualControl
    {
        p
        {
            tolerance   1e-5;
            relTol      0;
        }
        U
        {
            tolerance   1e-5;
            relTol      0;
        }
        "(k|omega)"
        {
            tolerance   1e-4;
            relTol      0;
        }
    }

    consistent          yes;
    turbOnFinalIterOnly true;
    momentumPredictor   yes;
}

relaxationFactors
{
    fields
    {
        p               0.5;
    }
    equations
    {
        "(U|k|omega)"   0.7;
        "(U|k|omega)Final" 1.0;
    }
}

cache
{
    grad(U);
}


// ************************************************************************* //

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