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  • snappyHexMesh网格贴合问题

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    2 Posts
    327 Views
    liu_shiqi1111L

    您好,请问解决了嘛?我现在也碰到了同样的问

  • snappyHexMesh以及paraview显示问题

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    12 Posts
    3k Views
    liu_shiqi1111L

    @huiyin 谢谢~

  • interFoam吐核

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    3 Posts
    262 Views
    U

    @学流体的小明 好的,谢谢

  • 3 Posts
    303 Views
    L

    @李东岳 感谢老师回复!动量预测是关掉了的。

    打开试了试,步长极小,残差也一直保持在一个值不下降,cumulative则很大,如下:

    Courant Number mean: 7.953414508e-05 max: 0.4993036972 deltaT = 4.979675437e-35 Time = 6.00001e-05 PIMPLE: iteration 1 DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 0.04941709914, No Iterations 29 DICPCG: Solving for pcorr, Initial residual = 0.03122316034, Final residual = 0.001556737496, No Iterations 121 DICPCG: Solving for pcorr, Initial residual = 0.006804280077, Final residual = 0.0003314734696, No Iterations 359 DICPCG: Solving for pcorr, Initial residual = 0.002308369425, Final residual = 9.709852492e-11, No Iterations 911 time step continuity errors : sum local = 1.793718362e-20, global = 1.178518414e-23, cumulative = 1.037419916e+19 smoothSolver: Solving for Ux, Initial residual = 3.985498772e-05, Final residual = 2.227155701e-11, No Iterations 1 smoothSolver: Solving for Uy, Initial residual = 6.302253167e-05, Final residual = 2.385619185e-11, No Iterations 1 GAMG: Solving for p, Initial residual = 0.004038713667, Final residual = 0.0001722133227, No Iterations 18 GAMG: Solving for p, Initial residual = 0.0005583071565, Final residual = 2.673668049e-05, No Iterations 34 GAMG: Solving for p, Initial residual = 9.485975434e-05, Final residual = 4.53317788e-06, No Iterations 33 GAMG: Solving for p, Initial residual = 2.596708738e-05, Final residual = 1.231466526e-06, No Iterations 38 time step continuity errors : sum local = 7.929103562e-15, global = -8.302368146e-16, cumulative = 1.037419916e+19 GAMG: Solving for p, Initial residual = 0.003717218882, Final residual = 0.000164557501, No Iterations 17 GAMG: Solving for p, Initial residual = 0.0005378364039, Final residual = 2.53035408e-05, No Iterations 34 GAMG: Solving for p, Initial residual = 9.265726415e-05, Final residual = 4.535601234e-06, No Iterations 36 GAMG: Solving for p, Initial residual = 2.556961887e-05, Final residual = 9.918214454e-11, No Iterations 548 time step continuity errors : sum local = 6.482264028e-19, global = 6.603865839e-20, cumulative = 1.037419916e+19 PIMPLE: iteration 2 ... PIMPLE: iteration 50 smoothSolver: Solving for Ux, Initial residual = 1.226945138e-10, Final residual = 6.6691269e-16, No Iterations 1 smoothSolver: Solving for Uy, Initial residual = 1.651845516e-10, Final residual = 3.177048458e-16, No Iterations 1 GAMG: Solving for p, Initial residual = 0.000949721577, Final residual = 4.516299707e-05, No Iterations 41 GAMG: Solving for p, Initial residual = 0.0004457930337, Final residual = 2.206483819e-05, No Iterations 23 GAMG: Solving for p, Initial residual = 7.977007558e-05, Final residual = 3.747481321e-06, No Iterations 36 GAMG: Solving for p, Initial residual = 2.418915618e-05, Final residual = 1.162060008e-06, No Iterations 48 time step continuity errors : sum local = 7.482194647e-15, global = -7.221446192e-16, cumulative = 1.037419916e+19 GAMG: Solving for p, Initial residual = 0.003705959955, Final residual = 0.0001646823634, No Iterations 17 GAMG: Solving for p, Initial residual = 0.0005377574684, Final residual = 2.535476181e-05, No Iterations 34 GAMG: Solving for p, Initial residual = 9.241219827e-05, Final residual = 4.525895839e-06, No Iterations 36 GAMG: Solving for p, Initial residual = 2.542969083e-05, Final residual = 9.774400044e-11, No Iterations 548 time step continuity errors : sum local = 6.388632178e-19, global = 6.502735317e-20, cumulative = 1.037419916e+19 PIMPLE: not converged within 50 iterations ExecutionTime = 21923.2 s ClockTime = 21963 s Courant Number mean: 7.964991508e-05 max: 0.4989139005 deltaT = 4.99051583e-35 Time = 6.00001e-05

    看到站内其它的帖子,试了试有量纲/无量纲计算(此前圆柱直径0.05,nu=50;改为圆柱直径0.0005,nu=0.5),也无法收敛。

    走投无路试了一下StarCCM,多低雷诺数都能算,和OpenFOAM那些能收敛的算例比得还贼好

  • 限制区域内提高重叠网格质量

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    1 Posts
    95 Views
    C

    各位好,我现在设想一个工况是在水深非常浅,同时水深与船舶吃水非常小(大约1.2)的情况,在设置重叠部分也即船舶部分网格时,blockmesh需要画的比较小,底部与船舶底部很接近,这就造成了snappyhexmesh后船舶下部的网格质量很差,请问有没有什么办法或者思路来改善网格质量呢,如有相似问题的朋友欢迎讨论,谢谢!261e3ad06976a58e400a1fc15243dc1.png 78823dc1464db8ab58735e54dcd17d2.png efa88c4c50ed4254badb8dbc8db3089.png

  • overinterdymfoam的一些疑问

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    6 Posts
    400 Views
    C

    @学流体的小明 好的,非常感谢解答

  • 水槽的速度变化感觉有错误

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    13 Posts
    1k Views

    我也在算类似的问题,是不是给定进口水位和流量的设置方法不对

  • interFoam如何初始化流场

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    1 Posts
    134 Views

    用interFoam计算带自由液面的倒虹吸,参考其他人边界设置,往往是入口给定流量(流速),出口给定水位(alpha.air)。这种设置方式如果通过手动设置(setFields)往往因初始流场不好极易发散,有没有办法能跟Fluent一样通过混合初始化得到一个初始场保证计算能够进行下去。(openFoam好像可以通过potentialFoam初始化场,但是这个对于interFoam也可以使用吗)79538e5a-b907-420a-8777-c7a72dd6011f-image.png

  • 关于buoyantPimpleFoam的几个问题

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    19 Posts
    4k Views
    L

    @cccrrryyy谢谢前辈

  • NSRFG在OF里面计算出现的问题

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    6 Posts
    435 Views
    疏影横斜水清浅

    你好,请问你编写的NSRFG,在使用时计算域是多大,网格尺度是多大,能否在整个计算域上保持低耗散甚至无耗散么

  • mapFields报错

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    2 Posts
    147 Views
    Z

    参考之前大神发的帖子就可以解决了
    https://www.cfd-china.com/topic/6750/mapfield报错

  • 9 Posts
    1k Views

    @jxzs_zy 在开发,好像还没正式发布。Added dynamicPolyRefinementFvMesh

  • 4 Posts
    352 Views
    Z

    问题找到了,对于这个算例,在滤波尺度的选择中,不能够使用剪切层调整亚格子长度尺度修正,但是别的文献中有人使用过,目前没有找到原因。

  • 17 Posts
    4k Views
    W

    你好,请问这个问题解决了吗?

  • 2 Posts
    278 Views
    S

    您好,您解决了吗

  • openfoam监测某个面上的涡量数据

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    2 Posts
    341 Views
    S

    您好,您解决了吗

  • 15 Posts
    7k Views
    S

    @BznW 您好。打扰一下,您解决了吗

  • 1 Posts
    76 Views
    L

    前一段时间搭建了流化床求解器(燃烧、密相颗粒流动求解器,下称newSolver),目前需要对这个求解器进行冷态颗粒流动的验证(常温,关闭化学反应、燃烧和传热)。通过验证发现颗粒轴向速度和实验吻合较好,但是气相压降差距很大,而使用MPPICFoam计算相同的case可以得到准确的压降(稳定时newSolver比MPPICFoam压降高两倍多)。

    为了找到问题所在,于是关闭颗粒计算纯气体流动的速度和压降,发现newSolver和MPPICFoam计算得到的气相速度相同但是压降有一定差距。因此猜测是气相压力方程计算的问题。

    由于newSolver是基于coalChemistryFoam流体方程加入alpha的修改的,纯气体流动情况下alpha=1。为了排除我修改方程所导致的错误,因此用coalChemistryFoam(关闭化学反应、燃烧和传热)计算纯气体流动看能否得到准确的结果。结果发现压降仍然有差距。

    难道coalChemisryFoam变密度的求解器无法计算常密度的情况吗?coalChemistryFoam是反应所导致的密度变化,关闭化学反应按理说密度应该是不变的,为何计算结果与实际差距大?常温纯气体流动压降都不准,加上化学反应燃烧后压降会准吗?

    MPPICFoam压力方程

    fvScalarMatrix pEqn ( fvm::laplacian(alphacf*rAUcf, p) == fvc::ddt(alphac) + fvc::div(alphacf*phiHbyA) );

    coalChemistryFoam压力方程

    fvScalarMatrix pEqn ( fvm::ddt(psi, p) + fvc::div(phiHbyA) - fvm::laplacian(rhorAUf, p) == coalParcels.Srho() + fvOptions(psi, p, rho.name()) );

    纯气体流动验证的几何模型和网格如下图所示
    图片1.png

    请各位大佬指教!

  • 粒子与网格归属问题

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    27 Posts
    5k Views
    T

    这段用来统计网格单元内粒子个数的代码,编译的路径是什么,求东岳老师指导

  • 使用swak4foam中的funkySetFields

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    1 Posts
    90 Views
    Z

    基于interFoam求解器,添加了标量场S,在模拟了一段时间后,得到了两相流体分布,再使用swak4foam中的funkySetFields,把标量赋值到alpha1流体中,另一相不考虑,设置如下:
    b8c93503-efa8-4a6d-9b18-7852dcb2d072-image.png
    运行后报错:
    15a01aae-36ee-42e4-8223-4fc9eba68dd9-image.png
    请问各位大神该如何解决呢?