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    Jack QQJ

    您好!我遇到类似问题,准备采用上述的第二种方法即topoSet + createPatch,但不太清楚具体应该如何操作,希望能指点一下,谢谢!@赵一铭 @小龙

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    来看看

  • 计算雷诺应力的表达式问题

    Algorithm
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    S

    @bestucan 感谢铁子的参考资料,已经弄明白了,之前的设置是对的。然而计算出来和试验值差异较大,总体分布的趋势一致,但数值上差了几十倍,之前听师兄说SST模型计算雷洛应力不准,计算结果来看确实不太准,也可能是我哪里设置的不对。:zoule:

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    F

    可能是显示的问题,保存后,关闭,重新打开,查看一下是否正确。

  • Aspect ratio 达到300多,如何调小呢

    Meshy
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    S

    @cfd-china
    恩恩,:laughing:

  • 有人用过of里的fft吗

    OpenFOAM
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    W

    写个类调用下fftw的函数接口就好了

  • 请教OpenFOAM不同网格之间场映射的原理

    OpenFOAM
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    李东岳

    meshToMeshInterpolate.C 可以看看这个内容,对,就是插值

  • 当量比的设置

    Algorithm
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    liujunCFDL

    @liujunCFD Snipaste_2021-03-04_11-27-23.png

  • ANSYS 超算平台的使用

    CFD彩虹条
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    V

    @桑葚熟了 目前没有用这些集群了,天河没用过,北京超算云那边感觉服务和价格都还不错,EasyCAE这边很久之前用的了之前价格有点小贵,现在不清楚了。

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    书生kao

    应该不会吧,我之前用的dell工作站,CPU是e5-2697v3,双路,windows系统,开了超线程,两颗CPU都可以调用,

  • 关于pbm群体平衡模型的问题

    Fluent
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    AlexA

    @东岳 :huahua: got it

  • UCSD-SDSU 联合博士项目招生

    CFD彩虹条
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    O

    Job description
    We provide the opportunity for the joint Ph.D. program between UCSD and SDSU.

    Research motivation
    Do you know that measurement in a turbulent environment has its own "sixth
    sense"? In fluid dynamical systems, measurements can be used to figure out
    events that happened far away from the probing location.
    Through state-of-art data assimilation techniques, we can trace back the origin
    of any information we have measured. We used this technique to locate the
    release of a pollution release, and reconstruct unknown flow fields from limited
    measurements.

    Are you self-motivated to do a Ph.D. in interdisciplinary researches about fluid
    dynamics, inverse problems, and optimization? We are looking for Ph.D. students
    that are willing to spend time studying in an encouraging and creative
    environment!

    There has been a long-hovering question about how to combine experimental
    measurements with numerical simulations. Especially in terms of designing a
    turbulence model that agrees with experimental studies. In addition, the design
    of sensor networks or sensor weighting can be optimized in terms of the amount
    of information obtained.
    In this Ph.D. project, you will develop novel simulation techniques that combine
    machine learning techniques with data assimilation.

    The required skills and preferred profile
    We are looking for self-motivated young researchers from mechanical
    engineering, aerospace engineering, computational physics, applied mathematics,
    or other closely related areas.

    Familiar with MATLAB and FORTRAN with MPI. C++ and python is a plus. Good conceptual understanding of calculus and linear algebra. Experience with simple machine learning algorithms. Good communication skills including presentation skills, academic writing
    with latex or word. Please note that the GRE is required for all JDP applicants and cannot be
    waived. Having a part-time hobby is a plus.

    Location
    Work is carried out in the Data Assimilation group at Aerospace Engineering, San Diego State University.
    We study various inverse problems in fluid dynamics using numerical simulations
    with the discrete adjoint operator.
    For further information, please visit us at
    https://qiwang.sdsu.edu/

    Information and application
    Interested applicants should visit
    https://www.engineering.sdsu.edu/admissions/jointdoc_areomech.aspx
    for more details about applying for the joint program.
    Meanwhile, please reach out to Qi Wang (qwang4@sdsu.edu), including:
    • A short description of your qualifications and motivation to apply for this
    position.
    • CV or resume.
    • Transcripts from your Bachelor and Master degrees.
    Selected candidates will be invited to an interview and should prepare a
    scientific presentation as part of the requirements.

    We highly value diversity at our university. Applicants from all backgrounds are
    welcomed.

  • Rhie-Chow interplation

    OpenFOAM
    1
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    C

    Original RC interplation
    No time dependency, No relaxation of the velocity field:

    // Rhie-Chow interplation phi = (U_avg_f & mesh.Sf()) - ( (DUf*( gradp_f - gradp_avg_f)) & mesh.Sf() );

    Time dependency, relaxation of the velocity field:

    // Rhie-Chow interplation phi = (U_avg_f & mesh.Sf()) - ( (DUf*( gradp_f - gradp_avg_f)) & mesh.Sf() ) + (scalar(1) - URFU)*(phi.prevIter() - (U_avg_prevIter_f & mesh.Sf())) + DTf*( phi_old - (U_old_f& mesh.Sf()));

    OpenFOAM
    No time dependency, with or without relaxation of the velocity field (check simpleFoam solver):

    surfaceScalarField phiHbyA("phiHbyA", fvc::interpolate(HbyA) & mesh.Sf());

    Questions: Where is the second term of the original RC? Where is the third term of the original RC if taking the relaxation of the velocity field into consideration?

    Time dependency, relaxation of the velocity field (check pisoFoam solver):

    surfaceScalarField phiHbyA ( "phiHbyA", (fvc::interpolate(HbyA) & mesh.Sf()) + fvc::ddtPhiCorr(rAU, U, phi) );

    Questions: ddtPhiCorr takes the function of (the third term+the fourth term of the original RC)? I guess NO. Let's recall the definition of ddtPhiCorr:

    tmp<fluxFieldType> ddtPhiCorr ( new fluxFieldType ( ddtIOobject, rDeltaT * this->fvcDdtPhiCoeff(U.oldTime(), phiAbs.oldTime()) * ( fvc::interpolate(rA*rho.oldTime())*phiAbs.oldTime() - ( fvc::interpolate(rA*rho.oldTime()*U.oldTime()) & mesh().Sf() ) ) ) );

    Look like ddtPhiCorr returns the following codes:

    fvcDdtPhiCoeff*DTf*( phi_old - (U_old_f& mesh.Sf()));

    Last question: How to take the effect of relaxation of the velocity field into ddtPhiCorr?
    谢谢

  • 有朋友做流固耦合吗

    Algorithm
    3
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    N

    感谢版主哦 :146:

  • 《无痛苦N-S方程笔记》小错误

    Algorithm
    1
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    今天空闲时间又看了一遍笔记发现有些笔误:
    P9-第三章第一节第二段第五行“将手竖直的防止在水中” 应为“将手竖直的放置在水中”

  • 关于涡的各种复数

    CFD彩虹条
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    bestucanB

    Screenshot_20211204_182532_cn.dictcn.android.digitize.oxford_oalecd9_17203.jpg

  • 0 赞同
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    L

    可以尝试利用ON_DEMAND宏 直接编辑一个dpm的初始化.inj 然后利用dpm的入射方法下拉菜单中的file导入实现一个比较好的初始化

  • 求一个win10可用的ANSYS下载地址

    Fluent
    21
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    P

    @东岳 按照教程安装ansys 17.2 后,fluent可以正常打开,但是单独打开OCEM时,报如下错误:

    ICEM_ACN is "/opt/ansys_inc/v172/icemcfd/linux64_amd". Hallo root. ANSYSLIC_DIR is set to /opt/ansys_inc/shared_files/licensing LD_LIBRARY_PATH is "/opt/ansys_inc/v172/icemcfd/linux64_amd/lib:/opt/ansys_inc/v172/icemcfd/linux64_amd/bin:/opt/ansys_inc/v172/icemcfd/linux64_amd/dif/iges:/opt/ansys_inc/v172/icemcfd/linux64_amd/../../Framework/bin/Linux64". args = libGL error: unable to load driver: swrast_dri.so libGL error: failed to load driver: swrast Window information: depth = 24 class = 4 visual depth = 24 class = 4 X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 154 (GLX) Minor opcode of failed request: 3 (X_GLXCreateContext) Value in failed request: 0x0 Serial number of failed request: 4785 Current serial number in output stream: 4789 Exit from ICEM CFD

    我的机子没有独显,用的是集显,会是这个原因吗,还请各位大神帮忙解答一下。

  • ICEM CFD中,关联(associate)的作用?

    Meshy
    2
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    C
    有的时候,某些内部的情况,没有几何,但是需要对网格进行一些处理,就需要手动的在不能关联的情况下,切一下。 某些需要投影的情况,比如地面上悬空的一个圆筒。在地面上只有圆筒的投影,也不存在几何关系。需要把edge投影过去,就需要spline方法。
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    N

    我转换ensight完成之后发现,只能读出几何模型,里面并没有数据,这是怎么回事