OpenFOAM

4.5k Topics 26.4k Posts
  • 7 Posts
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    这图应该指的是在网格分辨率足够的情况吧,如果分辨率不够,在0cell和1cell之间不会只夹着一个0,1之间的cell

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    计算完毕后,规定任意一条直线及点数,如何插值求出直线上任意一点的值?

    特别是计算区域分为几个小的区域,每个区域内有不同的物性参数的情况如何计算?

  • 读取速度矢量时出现浮点溢出

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    @李东岳
    的确奇怪,我现在都不知道为什么纯粹进行值之间的交换会出现问题,又没有显示命名的重复,
    不过我把发生错误的变量名字改了以后,错误就不在出现,虽然解决了,但还是对于错误的原因存疑。

  • Foam::sigSegv::sigHandler(int)错误

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    你好,请问你这个问题解决了吗?

  • 对MRF MixVessel 2D算例的疑问

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    你在MRFProperties里面或者fvoptions里面需要定义旋转的区域,paraview是显示的那个效果那个变不了。你可以把结果当做稳态时候的结果。或者搅拌器叶片转到某一个时刻,流场就是这个样子的。

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    @wwzhao 谢谢BZ!我试试~

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    好像以前见过一个类似的帖子,下面那个value 是没用的,主要用于paraview读取,你随便写100也可以。

  • fluent网格导入问题

    3 Posts
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    这个问题通常是由于内存不够引起的崩溃,你机器的内存多大?算例的网格多大?

  • interFoam中的jump conditions怎么处理

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    例如下面的两相界面处的jump condition,在表面张力系数σ不为常值函数时,沿界面方向的表面张力作用不能被忽略
    [μ∇u · n] = ∇s σ
    其中∇s =(I - nn)∇,表示表面梯度算子
    在interFoam中表面张力系数为常值函数,用CSF模型计算法向jump condition,想知道在多数CFD计算中,这种jump condition都会怎么处理?

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    好的 谢谢 我去看一下

  • 4 Posts
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    @mohui 我是基于那个方程进行修改添加一些,只不过它本身存在一些问题,当我设置1的时候温度正常

  • 关于k-omega 边界条件的设定

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    可以,so?

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    @李东岳 前辈,我一直用pyFoam来观察残差,我猜的这个bounded variable plot出现是因为计算出现了不稳定,如果这个bounded量计算没过界就不会出现。:confused:

    另外观测压力等物理量的残差如下,这个就比较好理解了:cheeky:

    0_1508035857600_WechatIMG15956.jpeg

  • 6 Posts
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    @我也不知道吧 好的,我加你。

  • 大涡模拟中如何产生湍流?

    4 Posts
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    我认为这个force应该是用来维持湍流的并不是产生湍流,否则没有这一项的话湍流会被粘性耗散掉。如果初始的速度场没有用boxTurb产生随机场的话,而是均匀的速度为零的速度场的话,根本算不出湍流。

    这个我还不确定,你可以不用boxturb,然后用dnsFoam算一下他那个tutorial看看有没有湍流出来。

    想问一下这一段代码是如何定义force的?

    目前只知道基于快速傅里叶变换,更深的代码还没看 :cheeky:

  • 如何在终端打开多个eps?

    1 Posts
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    gv只能打开一个eps

  • 表面活性剂影响液滴变形模拟

    6 Posts
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    @李东岳 除了添加力,还需要求解界面上表活剂输运方程,具体的介绍(James, Ashley J, Lowengrub, et al. A surfactant-conserving volume-of-fluid method for interfacial flows with insoluble surfactant[J]. Journal of Computational Physics, 2004, 201(2):685-722. )。怎么求解输运方程这一块我不知道怎么处理。

  • 关于interPhaseChangeFoam的动量方程

  • 12 Posts
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    @random_ran 这个词我一直在用,哈哈,逆压梯度

  • 粘性耗散项

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    @李东岳 就是考虑粘性耗散项,粘性耗散热也是热源

  • 标量场求解入口网格异常问题

    3 Posts
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    类似这种求解不正确的问题很难判断 :confused:

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    这个看起来需要在你的局部区域做一个网格,然后mapField过去。

  • 关于log的基础问题

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    linux命令。同时将输出显示在屏幕上,你百度一下就明白了

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    @李东岳 这个装在一个cluster上,好久没维护了,不是很懂cluster不敢乱弄,怕万一弄崩了,没人会rebuild了。。。

  • 如何在paraview中显示mesh编号

    4 Posts
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    不是point,有一个手动选取cell的按钮..

  • 时变边界条件

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    @wwzhao 好的,解决了

  • 9 Posts
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    自己挖的坑自己填回去。。。。。。。。。。。。。

    我今天发现是我自己定义的TELF函数出了问题,所以计算出来的结果有问题。
    但是这种方法加入状态方程我实践过的确是可行的。
    就是换了以后,连续性误差的地方会变的非常怪,查了continuityErr这个文档,发现里面计算连续性误差还是使用rho-thermo.rho所以会出现误差值十分大,
    目前还在想着这么去改thermo下的东西,因为自己不能把黏性系数和普朗数设成固定值,
    怎样把这些thermo文档下设置函数还在研究中。

  • 7 Posts
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    @李东岳 多谢李老师!

  • Sliding Mesh 不能进行并行计算

    20 Posts
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    @李东岳 谢谢大神的解答:happy:

  • 8 Posts
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    需将2进制网格文件转换为ascii码格式

    在controlDict下把format改为ascii,然后运行foamFormatConvert就可以转换了。

  • 1 Posts
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    https://www.aaar.org/awards/annual-awards/ast-outstanding-publication-award/

    AS&T Outstanding Publication Award

    AS&T's Outstanding Publication Award is awarded annually to one paper published in Aerosol Science and Technology (AS&T) without regard to publication date. The award recognizes papers that have had a significant impact on the field. Nominations should include a single letter and a citation of approximately 100 words. The letter is limited to three pages and may be signed by more than one person. The citation is a succinct summary of the significance of the paper, suitable for dissemination with the award announcement. Self-nominations are not permitted.

    AS&T's Editor-in-Chief presents the AS&T Outstanding Publication Award at the annual AAAR meeting. It consists of a certificate for each co-author, one plaque to be used at the discretion of the co-authors, and monetary award of $2000. In addition, it is announced in AS&T along with the rationale for its choice.

    AS&T Publications recognized by this award:

    2016

    Robert McGraw, Description of Aerosol Dynamics by the Quadrature Method of Moments

    2015

    Shih Chen Wang and Richard C. Flagan. "Scanning Electrical Mobility Spectrometer" Aerosol Science and Technology, *13*, 230-240 (1990).

  • 矩方法不稳定性的讨论

    1 Posts
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    0_1506417017782_捕获.JPG

    See: Generalization and Numerical Investigation of QMOM

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    @李东岳 好的,我在看看。植入是整套算法都植入过来,那难度实在太大了。

  • 10 Posts
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    @一二 好的,非常感谢

  • MULES算法中的const RhoType &rho

    5 Posts
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    @wwzhao 谢谢:happy:

  • 计算出错

    5 Posts
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    @李东岳 不是虚拟机 装的双系统(ubuntu16.04) 正在监控内存试试看

  • 9 Posts
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    @xiaofenger 这是同一时刻不同位置的速度矢量图,我不知道怎么画

  • 请问这是OF中的假扩散现象吗?

    3 Posts
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    @李东岳 东岳老师你好,我的内部改动了,但是理论上应该不会引起这个问题。

    主要是可以观察到相体积分数的扩散(波还没传过来)。可能和我这个地方的网格有关系?我再去看看

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    如果你完全没用过OpenFOAM,并且正在考虑,就很难办了。一般新手入行OpenFOAM,很多都是选择OpenFOAM-学习OpenFOAM-放弃OpenFOAM这个过程。

  • 4 Posts
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    http://www.sciencedirect.com/science/article/pii/S0009250917305444

    2.3节,其中方程24的最后一项对应p_rghEqnComp1和p_rghEqnComp2,只不过VOF里面求解的是p_rgh,你知道的。

  • 14 Posts
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    其他你的理解大体正确,·volScalarField和scalarField的区别仅仅在于volScalarField附加了边界的信息,scalarField`只是网格点的信息不包含边界。

  • 8 Posts
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    mesh.V()的单位是m³

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    关于cmake仍然是旧版:
    在~/.bashrc 里面为cmake添加过类似于export PATH=$HOME/OpenFOAM/platforms/linux64Gcc/cmake-2.8.8/bin:$PATH的命令了吗?添加之后source ~/.bashrc了吗?

  • 7 Posts
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    @Jacobian 非常感激您的帮助,好人一生平安!

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    @李东岳 好的 谢谢东岳老师

  • 5 Posts
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    @hurricane007 Thanks very much!

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    @程迪请问paraview可以改变结果的长宽比吗 中说:

    @CFDngu

    https://stackoverflow.com/a/35793646/4592964

    To do this you have to toggle the advanced properties, the small gear icon on the properties tab, look for "Scale" and choose each axis scale factor. Or you can simply use the properties search field (below the Apply button) and search "Scale" to show this property up.

    多谢!我去看一下

  • 关于unsteady rans

    1 Posts
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    最近做LES sensitivity test,比如网格从十米到五米到三米到一米,什么时候结果不太变化了,这个时候我们可以说SGS模型成功模拟了亚网格湍流,然后突然想到一个关于urans的经典的问题,比如跑一个urans,然后把时间步调的很小,网格也足够细致,这样跑出来的到底是个什么东西?换句话说,ns方程有时间项,单方程,双方程模型里也都有时间项,足够小的时间步到底意味着什么?

  • forAll 起到什么作用呢?

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    可以啊,Why not?

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    snappyHexMesh为何怎么划分 还是会出现不均匀的错误网格?。快疯了 求解答下0_1503045662410_屏幕快照 2017-08-18 下午5.38.07.png !

    这个是snappyHexMeshDic

    castellatedMesh true; // make basic mesh ? snap true; // decide to snap back to surface ? addLayers true; // decide to add viscous layers ? geometry // Load in STL files here { inlet.stl {type triSurfaceMesh; name inlet;} outlet.stl {type triSurfaceMesh; name outlet;} part1.stl {type triSurfaceMesh; name part1;} part2.stl {type triSurfaceMesh; name part2;} volume.stl {type triSurfaceMesh; name volume;} }; castellatedMeshControls { maxLocalCells 1000000; //max cells per CPU core maxGlobalCells 2000000; //max cells to use before mesh deletion step minRefinementCells 0; //was 0 - zero means no bad cells are allowed during refinement stages maxLoadUnbalance 0.1; nCellsBetweenLevels 1; // expansion factor between each high & low refinement zone // Explicit feature edge refinement // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ features // taken from STL from each .eMesh file created by "SurfaceFeatureExtract" command ( {file "inlet.eMesh"; level 0;} {file "outlet.eMesh"; level 0;} {file "part1.eMesh"; level 0;} {file "part2.eMesh"; level 0;} ); // Surface based refinement // ~~~~~~~~~~~~~~~~~~~~~~~~ refinementSurfaces // Surface-wise min and max refinement level { inlet {level (0 0);} outlet {level (0 0);} part1 {level (0 0);} part2 {level (0 0);} } resolveFeatureAngle 80; // Resolve sharp angles // Default 30 refinementRegions // In descending levels of fine-ness {} // was ((0.001 4) (0.003 3) (0.01 2)) locationInMesh (0.01 0 0); //to decide which side of mesh to keep ** allowFreeStandingZoneFaces true; } // Settings for the snapping. snapControls { nSmoothPatch 3; tolerance 2.0; nSolveIter 30; nRelaxIter 5; nFeatureSnapIter 10; // default is 10 // New settings from openfoam 2.2 onwards for SHMesh implicitFeatureSnap false; // default is false - detects without doing surfaceFeatureExtract explicitFeatureSnap true; // default is true multiRegionFeatureSnap false; // deafault is false - detects features between multiple surfaces } addLayersControls //add the PATCH names from inside the STL file so STLpatchName_insideSTLName { relativeSizes false; // was true layers { } expansionRatio 1.3; finalLayerThickness 0.00016; //was 0.00016 minThickness 0.00008; //was 0.00008 nGrow 0; // was 1 // Advanced settings featureAngle 80; // was 70 //- When not to extrude surface. 0 is flat, 90 is right angle. nRelaxIter 3; //- Max# of snapping relaxation iter. Should stop before upon reaching a correct mesh. nSmoothSurfaceNormals 1; nSmoothNormals 3; nSmoothThickness 10; maxFaceThicknessRatio 0.5; maxThicknessToMedialRatio 0.3; thickness to medial distance is large minMedianAxisAngle 130; nBufferCellsNoExtrude 0; nLayerIter 50; } meshQualityControls { maxNonOrtho 65; maxBoundarySkewness 20; maxInternalSkewness 4; maxConcave 80; minFlatness 0.5; minVol 1e-13; minTetQuality 1e-9; minArea -1; minTwist 0.02; minDeterminant 0.001; minFaceWeight 0.02; minVolRatio 0.01; minTriangleTwist -1; // Advanced nSmoothScale 4; errorReduction 0.75; } // Advanced debug 0; mergeTolerance 1E-6;