谢谢老师，已成功，继续学习案例

目前使用的版本是6。 想在管道流的出口和入口处设置时变边界条件，边界速度和压力的变化函数是一个三角形形式的傅里叶级数。请问在我使用的版本中使用哪种工具可以实现该类边界条件的设置，请各位老师指教。

@我是河滩 密度可以是任意值，不是1.225。计算雷诺数时，密度体现在粘性里，由miu,变为niu。

@lllwonderliquid 同意

@Hungryandfool 可以啊，欢迎交流 可以加我微信chenghui62000

不太很清楚你说的，治根只能重做网格，这面网格点的对齐要满足机器精度，双精度的时候误差要小于1e-16，非常的严格啊

@yfclark 谢谢

@l-j刘侃 在 气固耦合、颗粒、化学反应、UDF、DEM-FLUENT 中说： CFDDEM的 谢谢了，我自己先消化下。

两个比较好的可用来测试得实验。气泡塌缩得。把他包含在OKS 几何简单，数学模型复杂，验证算法利器 Numerical simulation of a collapsing bubble subject to gravity Bubble collapse near a solid boundary: a numerical study of the influence of viscosity Numerical investigation of an underwater explosion bubble based on FVM and VOF

@东岳 非常期待了哈哈哈

OpenFOAM新供能网格定向拉伸 https://www.openfoam.com/releases/openfoam-v1812/pre-processing.php 没有使用过snappyHexMesh工具画网格，最近在学习这个新功能，但是一直没有成功 我都模型是一个简单的矩形（blockMesh生成），我想把部分区域的网格只在竖直方向上加密网格 这应该怎么处理，麻烦各位前辈们指点一下 ，还有snappyHexMesh一定要和stl文件一起使用才能使用吗？

大家好，我想用interfoam求解器计算水流动，水池中有个障碍物，如果采用大涡模拟的方法，用什么模型比较合适呢？

没有修正压力系数。这是可以理解的因为库郎数的作用瞬态计算时间布长内的变化并没有稳态计算那么大。可以这样想： 如果修正压力系数 如果每次求解一次压力、更新一次速度 你就变成了SIMPLE

采用interFoam修改的求解器计算算例，遇到网格太小带来的壁面处压力问题（图中为第一个输出时间步（约0.0001 s）的压力分布，出现了不正常最大和最小压力）。 算例的壁面（BOTTOM）为锯齿状壁面，图中所示部分为倾斜向上的一小部分，壁面附近的网格精度约为1微米，压力场初始为0，压力和速度壁面处边界条件如下： p_rgh BOTTOM { type fixedFluxPressure; value uniform 0; } U BOTTOM { type fixedValue; value uniform (0 0 0); } 大家有没有遇到过这样的问题，有什么解决思路吗？

这不就是利用sample的功能提取数据进行简单的制图么？

计算圆管绕流，的流固耦合fsiFoam，库郎数和残差较大，第一个时间步长都计算不过去。使用了foam-extend3.1，迭代了30次都无法收敛，请教大神如何才能降低库郎数和残差让他收敛 Time = 0.00025, iteration: 30 Maximal accumulated displacement of interface points: 0.0030560221 GAMG: Solving for cellMotionUx, Initial residual = 0.91131119, Final residual = 0.00072219997, No Iterations 1 GAMG: Solving for cellMotionUy, Initial residual = 0.8372583, Final residual = 0.00018220686, No Iterations 4 GAMG: Solving for cellMotionUz, Initial residual = 0.83907808, Final residual = 0.00074754473, No Iterations 3 GAMG: Solving for cellMotionUx, Initial residual = 0.005840706, Final residual = 3.3755319e-06, No Iterations 5 GAMG: Solving for cellMotionUy, Initial residual = 0.0014240355, Final residual = 9.3916646e-07, No Iterations 5 GAMG: Solving for cellMotionUz, Initial residual = 0.0037156885, Final residual = 2.0135642e-06, No Iterations 5 Evolving flow model Courant Number mean: 0.12920764 max: 2.1173853 velocity magnitude: 5.8284982 DILUPBiCG: Solving for Ux, Initial residual = 0.00050711718, Final residual = 6.735853e-07, No Iterations 3 DILUPBiCG: Solving for Uy, Initial residual = 0.00036428585, Final residual = 8.7737472e-07, No Iterations 3 DILUPBiCG: Solving for Uz, Initial residual = 0.0016313381, Final residual = 1.5961465e-07, No Iterations 4 GAMG: Solving for p, Initial residual = 0.00108613, Final residual = 7.8685153e-07, No Iterations 8 GAMG: Solving for p, Initial residual = 0.00019371718, Final residual = 5.401407e-07, No Iterations 5 time step continuity errors : sum local = 2.3989423e-09, global = -6.1017797e-11 GAMG: Solving for p, Initial residual = 0.0003988323, Final residual = 4.1675183e-07, No Iterations 7 GAMG: Solving for p, Initial residual = 4.9145888e-05, Final residual = 5.1093922e-07, No Iterations 4 time step continuity errors : sum local = 2.270261e-09, global = 2.9434889e-10 GAMG: Solving for p, Initial residual = 8.1696621e-05, Final residual = 5.3236835e-07, No Iterations 5 GAMG: Solving for p, Initial residual = 7.3969174e-06, Final residual = 4.311989e-07, No Iterations 2 time step continuity errors : sum local = 1.915783e-09, global = 2.5707342e-10 DILUPBiCG: Solving for epsilon, Initial residual = 0.00031614333, Final residual = 1.050823e-07, No Iterations 3 DILUPBiCG: Solving for k, Initial residual = 0.0012814958, Final residual = 4.2631276e-07, No Iterations 3 Setting traction on solid patch Total force (fluid) = (-459.15346 -1.0986824 6.7686718e-06) Total force (solid) = (459.1594 1.0991446 -6.379015e-06) Time = 0.00025, iteration: 30 Maximal accumulated displacement of interface points: 0.065467478 GAMG: Solving for cellMotionUx, Initial residual = 0.79783225, Final residual = 4.939853e-06, No Iterations 1 GAMG: Solving for cellMotionUy, Initial residual = 0.98797867, Final residual = 0.00038088437, No Iterations 1 GAMG: Solving for cellMotionUz, Initial residual = 0.99921705, Final residual = 0.00017911438, No Iterations 1 GAMG: Solving for cellMotionUx, Initial residual = 1.2711546e-05, Final residual = 4.7196981e-07, No Iterations 3 GAMG: Solving for cellMotionUy, Initial residual = 0.00037198031, Final residual = 6.6720231e-07, No Iterations 4 GAMG: Solving for cellMotionUz, Initial residual = 0.00017081592, Final residual = 5.0439818e-07, No Iterations 4 Evolving flow model: consistentIcoFlow Courant Number mean: 0.0090301047 max: 0.065159774 velocity magnitude: 0.057301147 DILUPBiCG: Solving for Ux, Initial residual = 0.0026059227, Final residual = 7.4154757e-07, No Iterations 1 DILUPBiCG: Solving for Uy, Initial residual = 0.014165186, Final residual = 4.8137205e-09, No Iterations 2 DILUPBiCG: Solving for Uz, Initial residual = 0.008498764, Final residual = 2.0793996e-09, No Iterations 2 Consistent backwardDdtPhiCorr GAMG: Solving for p, Initial residual = 0.051049597, Final residual = 9.9704343e-07, No Iterations 126 GAMG: Solving for p, Initial residual = 0.020685413, Final residual = 9.673727e-07, No Iterations 32 time step continuity errors : sum local = 3.1839476e-08, global = -2.5816328e-09 Consistent backwardDdtPhiCorr GAMG: Solving for p, Initial residual = 0.0063770573, Final residual = 9.5379753e-07, No Iterations 28 GAMG: Solving for p, Initial residual = 0.0017021007, Final residual = 7.7514105e-07, No Iterations 7 time step continuity errors : sum local = 2.5870532e-08, global = -3.2020508e-09 Consistent backwardDdtPhiCorr GAMG: Solving for p, Initial residual = 0.00032173865, Final residual = 8.340539e-07, No Iterations 6 GAMG: Solving for p, Initial residual = 6.000076e-05, Final residual = 9.9786163e-07, No Iterations 3 time step continuity errors : sum local = 3.324389e-08, global = 1.4105992e-09 Setting traction on solid patch Total force (fluid2) = (-0.032864973 -7.3826261e-06 -8.2297438e-06) Total force (solid) = (0.032882651 4.759419e-06 8.2338506e-06) Evolving stress model DICPCG: Solving for D, Initial residula = 9.4105628e-05, Final residual = 7.0815126e-05, No outer iterations = 62 Max relative residual = 0.00010949815, Relative residual = 9.6889967e-08, enforceLinear = 0 here. rheol Current fsi relative residual norm: 0.99756477 there. rheo? ExecutionTime = 393.24 s ClockTime = 393 s forces output: forces(pressure, viscous)((459.60513 1.099789 -6.5750415e-06) (0.45167049 0.0011065994 1.9363028e-07)) moment(pressure, viscous)((-0.27504867 114.90181 -0.00011651384) (-0.00027659408 0.11291678 -1.6157571e-05)) forceCoeffs output: Cd = 13.047032 Cl = 0.031220971 Cm = -7.5250194e-06 Time = 0.0005 Time = 0.0005, iteration: 1 Modes before clean-up : 28, modes after clean-up : 28 Maximal accumulated displacement of interface points: 131520.66 GAMG: Solving for cellMotionUx, Initial residual = 0.99999997, Final residual = 0.00059804825, No Iterations 3 GAMG: Solving for cellMotionUy, Initial residual = 1, Final residual = 0.00018112037, No Iterations 4 GAMG: Solving for cellMotionUz, Initial residual = 1, Final residual = 0.00071242028, No Iterations 3 GAMG: Solving for cellMotionUx, Initial residual = 0.00030676863, Final residual = 6.1484473e-07, No Iterations 4 GAMG: Solving for cellMotionUy, Initial residual = 9.0611988e-05, Final residual = 9.4170358e-07, No Iterations 3 GAMG: Solving for cellMotionUz, Initial residual = 0.00035888355, Final residual = 5.823629e-07, No Iterations 4 Evolving flow model Courant Number mean: 4.4963525 max: 8386.7294 velocity magnitude: 223638.76 DILUPBiCG: Solving for Ux, Initial residual = 0.99999848, Final residual = 1.0000271, No Iterations 1000 DILUPBiCG: Solving for Uy, Initial residual = 0.99997733, Final residual = 0.99997733, No Iterations 1000 DILUPBiCG: Solving for Uz, Initial residual = 0.99999992, Final residual = 0.99999992, No Iterations 1000 Floating point exception (core dumped) * 列表 外侧流体 epsilon k nut p pointmotion U U INLET inletOutlet inletOutlet calculated zeroGradient fixedValue fixedValue OUTLET inletOutlet inletOutlet calculated fixedValue fixedValue zeroGradient FRONT_AND_BACK epsilonWallFunction kqRWallFunction nutkWallFunction zeroGradient fixedValue fixedValue UP_AND_DOWN epsilonWallFunction kqRWallFunction nutkWallFunction zeroGradient fixedValue fixedValue INTERFACE_INTERFACE epsilonWallFunction kqRWallFunction nutkWallFunction zeroGradient fixedValue movingWallVelocity 内侧流体 epsilon k nut p pointmotion U U INLET inletOutlet inletOutlet calculated zeroGradient fixedValue fixedValue OUTLET inletOutlet inletOutlet calculated fixedValue zeroGradient zeroGradient INTERFACEWATER epsilonWallFunction kqRWallFunction nutkWallFunction zeroGradient fixedValue movingWallVelocity 固体 D pointD 密度 弹性模量 泊松比 OUTERWALL tractionDisplacement calculated 6500 7.80E+10 0.37 INNERWALL tractionDisplacement calculated UP_AND_DOWN fixedValue fixedValue 控制条件为 application fsiFoam.rheo; startFrom startTime; startTime 0; stopAt endTime; endTime 0.42; deltaT 2.5e-4; writeControl runTime; writeInterval 2.5e-3; purgeWrite 0; writeFormat ascii; writePrecision 8; writeCompression uncompressed; timeFormat general; timePrecision 6; runTimeModifiable yes; adjustTimeStep yes; maxCo 0.01; maxdeltaT 2.5e-3; fsi设置如下 solidPatch OUTERWALL; solidZone OUTERWALL_zone; fluidPatch INTERFACE_INTERFACE; fluidZone INTERFACE_zone; solidPatch2 INNERWALL; solidZone2 INNERWALL_zone; fluid2Patch INTERFACEWATER; fluid2Zone INTERFACEWATER_zone; relaxationFactor 0.01; interfaceDeformationLimit 0; outerCorrTolerance 1e-6; nOuterCorr 20; interpolatorUpdateFrequency 0; //couplingScheme FixedRelaxation; //couplingScheme Aitken; couplingScheme IQN-ILS; couplingReuse 1; coupled yes;

@队长别开枪 好的，谢谢

@G8S7 究竟能不能用欧拉-欧拉模型来说明这个体系下固体颗粒的运动情况， 如果有实验图片的话更好判断。取决于固体颗粒粒径，相分数，粘度等。如果用你所说的VOF+欧拉-欧拉才能描述这一个过程，也是可以的。另一种方式是三相欧拉，在皮层熔体中对界面进行尖锐挤压处理。 另外，用什么模型取决你你关注的重点，如果关注内部的运动，皮层溶体不是重点用欧拉无妨，VOF也是有耗散。 At last, 几何很简单，是验证算法的利器，不用OpenFOAM可惜了。

@余正东 我都没听过 。。。

1 最近在尝试在dynamicKEqn模型中使用不同的滤波器，参照CFD-online上的帖子和LESfilter.H的设置更改了滤波器。 按理来说，根据dynamicKEqn头文件的说明如此可以更改用于亚格子动能的滤波器 但是出现了如下报错： #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/lib/x86_64-linux-gnu/libc.so.6" #3 Foam::sqrt(Foam::Field<double>&, Foam::UList<double> const&) at ??:? #4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::sqrt<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? #5 Foam::LESModels::dynamicKEqn<Foam::IncompressibleTurbulenceModel<Foam::transportModel> >::Ck(Foam::GeometricField<Foam::SymmTensor<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) const at ??:? #6 Foam::LESModels::dynamicKEqn<Foam::IncompressibleTurbulenceModel<Foam::transportModel> >::correctNut(Foam::GeometricField<Foam::SymmTensor<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? #7 Foam::LESModels::dynamicKEqn<Foam::IncompressibleTurbulenceModel<Foam::transportModel> >::correctNut() at ??:? #8 ? at ??:? #9 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #10 ? at ??:? Floating point exception (core dumped) 令人感到奇怪的是对于Smagorinsky模型更改滤波器就能正常运行。 2 另一处令我感到困惑的地方在于OpenFOAM中盒式滤波和高斯滤波居然使用同一参数进行开启，而这两者是完全不同的滤波器，OpenFOAM是如何做到区分两者的？