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小

各位前辈好！

本人利用openfoam计算水翼空化流动，输出了100个时刻的流场数据，目前想利用tecplot提取这100个时刻流场中下图这条监测虚线上的数据。这条虚线垂直距离水翼吸力面1mm。

监测点.png

目前的困难就是如何提取这条检测线上的数据呢？

自己之前截取水翼吸力面上的数据，直接利用slience截取水翼就可以，但现在监测线垂直距离水翼壁面有1mm，就不知道怎么处理了，希望各位前辈能够提供一点思路或者建议，十分感谢

小

刚刚自己又研究了一下，现在又出现了新的问题，请问一下大家openfoam中有关比内能的定义代码在哪里找呢？目前我只能找到compressibleInterFoam里面有关比焓he的定义，但具体求解代码在src里面找不到了？

小

各位前辈好！

本人目前主要研究空化中的激波问题，读论文的时候（论文链接：https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/numerical-study-of-cavitation-regimes-in-flow-over-a-circular-cylinder/C66ECA1BBE0036734834570F7DCE1683），
涉及到比内能与温度的公式2.4（下图），现在不明白水中比内能el与温度T的关系式是如何得到的呢？水的这个关系式为什么比气体的关系式多出一个Pc\rho_l呢？

有没有哪位前辈可以推荐一点参考资料呢？
XB4K$06@GHWPOQJPB97R{VH.png

小

@bestucan 前辈您好！很抱歉再次打扰您，针对您之前的回复，我认真研读了一下，但还是存在一些困难，还希望您能够指点一个思路，感激不尽！

我现在在用非线性SGS模型，为了防止计算崩掉，就要限制SGS模型计算的Tij，可是Tij是一个类型为 volTensorField的张量，我现在无法提取出来这个Tij的每一个分量，进行限制。

我刚刚简单试验了一下如下代码：

const volSymmTensorField S = symm(gradU);    

const volScalarField Z = S.zz();

，报错如下：

DNM.C: In member function ‘Foam::dimensionedVector Foam::compressible::LESNonlinearModels::DCNM::C(const volTensorField&) const’:
DNM.C:83:28: error: ‘const volSymmTensorField’ has no member named ‘zz’
 const volScalarField Z = S.zz();

我目前的思路是参考tensor的定义成员xx xy xz的思路，将volTensorField中也定义一个xx xy xz等9个分量，，但不知道这样可行否，，同时由于这个原始的湍流模型代码比较老（是2.4版本的），我如何能快速找到tensor 和 volTensorField的定义和代码呢？

希望前辈百忙之中再指点一下，谢谢！

小

@benqing 在 paraView-求展向平均问题中说：

@小考拉 paraview能不能做不清楚，但是可以写程序实现，下面是cfdonline上的程序，我用过，可以实现，你可以研究一下，源程序好像只有速度压力这些东西，alpha.water的话需要自己添加进去
https://www.cfd-online.com/Forums/openfoam-post-processing/106966-spanwise-averaging-three-dimensional-field.html

前辈您好！

我最近在研究您回复我的cfd online上的求解展向时均的代码，cfd online上面有两个代码，分别如下和，请问前辈您之前用的是哪一套代码呢？

我现在在研究第一套代码的spanwiseAvg.C文件，但里面的一些遍历网格单元的代码自己不是很清楚，，请问前辈有哪些资料可以参考学习一下呢？

另外在第一套代码中（spanwiseAvg.C）的file文件中为什么是EXE = $(FOAM_USER_APPBIN)/spanwiseAvg呢？感觉看起来编译的是个求解器，

自己的of代码基础比较薄弱，还望前辈能够赐教，感激不尽

小

哇，感谢前辈回复，我仔细去学习一下

小

各位前辈们好！

我现在定义了一个张量 volTensorField S,现在想输出其中的 S.xx()这个分量的值，查看了一些前辈之前的讨论帖子：链接文本

请问对于类型为volTensorField的张量S怎样输出它的分量S.xx（）呢？

小

@bestucan 感谢前辈的回复，目前问题已经解决

在编译OpenFOAM之前，需要先编译ThirdParty，但OpenFOAM WiKi中的Ubuntu18.04版安装教程里面好像并没有“编译ThirdParty这一步”，希望以后大家注意吧

小

各位前辈好！

我目前在Ubuntu18.04下面相安装openfoam3.0.0,参考了openfoamwiki有关在Ubuntu 18.04安装of 3.0.1的教程，教程连接：链接文本

自己一步步完全按照wiki上面的教程安装，安装到第14步编译openfoam的时候，编译一会就报错如下：

g++-5 -m64 -Dlinux64 -DWM_ARCH_OPTION=64 -DWM_DP -DWM_LABEL_SIZE=32 -Wall -Wextra -Wold-style-cast -Wnon-virtual-dtor -Wno-unused-parameter -Wno-invalid-offsetof -O3  -DNoRepository -ftemplate-depth-100  -IlnInclude -I. -I/home/abc/OpenFOAM/OpenFOAM-3.0.0/src/OpenFOAM/lnInclude -I/home/abc/OpenFOAM/OpenFOAM-3.0.0/src/OSspecific/POSIX/lnInclude   -fPIC -c reaction/reactions/makeLangmuirHinshelwoodReactions.C -o /home/abc/OpenFOAM/OpenFOAM-3.0.0/platforms/linux64GccDPInt32Opt/src/thermophysicalModels/specie/reaction/reactions/makeLangmuirHinshelwoodReactions.o
reaction/reactions/makeReactions.C: In function ‘void __static_initialization_and_destruction_0(int, int)’:
reaction/reactions/makeReactions.C:106:1: internal compiler error: 段错误
 }
 ^
g++-5: internal compiler error: 段错误 (program cc1plus)
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-5/README.Bugs> for instructions.
make: *** [/home/abc/OpenFOAM/OpenFOAM-3.0.0/platforms/linux64GccDPInt32Opt/src/thermophysicalModels/specie/reaction/reactions/makeReactions.o] Error 4
/home/abc/OpenFOAM/OpenFOAM-3.0.0/wmake/rules/General/transform:8: recipe for target '/home/abc/OpenFOAM/OpenFOAM-3.0.0/platforms/linux64GccDPInt32Opt/src/thermophysicalModels/specie/reaction/reactions/makeReactions.o' failed
make: *** 正在等待未完成的任务....
abc@abc-X11DAi-N:~/OpenFOAM/OpenFOAM-3.0.0$

麻烦哪位前辈能够指点以下怎么解决呢？谢谢

小

各位前辈好！

我在compressibleInterFoam中引入了空化源项，现在调用自己写的非线性SGS模型计算的时候，流场初始速度10m/s，计算一段时间后，maxU会突然增大，导致流场发散掉，下面是速度暴增的过程

MULES: Solving for alpha.water
Liquid phase volume fraction = 0.997517  Min(alpha.water) = 0.000412402  Max(alpha.water) = 1
  Min(alpha.vapor) = -8.20677e-13  Max(alpha.vapor) = 0.999588
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver:  Solving for T, Initial residual = 4.32259e-05, Final residual = 2.38488e-09, No Iterations 2
min(T) 290.144
GAMG:  Solving for p_rgh, Initial residual = 4.54434e-06, Final residual = 7.05483e-10, No Iterations 3
max(U) 13.9186
min(p_rgh) 1843.8
GAMGPCG:  Solving for p_rgh, Initial residual = 3.62757e-07, Final residual = 4.88638e-10, No Iterations 1
max(U) 13.9184
min(p_rgh) 1843.67
ExecutionTime = 275.32 s


 Integral of alpha.water = 0.00190802  [0 3 0 0 0 0 0]
fieldAverage fieldAverage1 output:
    Calculating averages

Courant Number mean: 0.00487524 max: 0.135574
Time = 0.011952

MULES: Solving for alpha.water
Liquid phase volume fraction = 0.997517  Min(alpha.water) = 0.000413145  Max(alpha.water) = 1
  Min(alpha.vapor) = -4.79172e-13  Max(alpha.vapor) = 0.999587
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver:  Solving for T, Initial residual = 4.324e-05, Final residual = 2.42709e-09, No Iterations 2
min(T) 290.146
GAMG:  Solving for p_rgh, Initial residual = 5.42286e-06, Final residual = 7.32723e-10, No Iterations 3
max(U) 26.57
min(p_rgh) 1813.11
GAMGPCG:  Solving for p_rgh, Initial residual = 3.66982e-07, Final residual = 5.21535e-10, No Iterations 1
max(U) 25.4251
min(p_rgh) 1817.97
ExecutionTime = 275.6 s


fieldAverage fieldAverage1 output:
    Calculating averages

Courant Number mean: 0.00487537 max: 0.135663
Time = 0.011953

MULES: Solving for alpha.water
Liquid phase volume fraction = 0.997517  Min(alpha.water) = 0.000412369  Max(alpha.water) = 1
  Min(alpha.vapor) = -8.14016e-13  Max(alpha.vapor) = 0.999588
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver:  Solving for T, Initial residual = 4.32537e-05, Final residual = 2.41625e-09, No Iterations 2
min(T) 290.148
GAMG:  Solving for p_rgh, Initial residual = 5.31025e-06, Final residual = 6.64697e-10, No Iterations 3
max(U) 20.2828
min(p_rgh) 1797.39
GAMGPCG:  Solving for p_rgh, Initial residual = 3.95326e-07, Final residual = 5.53382e-10, No Iterations 1
max(U) 20.6401
min(p_rgh) 1803.66
ExecutionTime = 275.88 s


fieldAverage fieldAverage1 output:
    Calculating averages

Courant Number mean: 0.00487547 max: 0.135752
Time = 0.011954

MULES: Solving for alpha.water
Liquid phase volume fraction = 0.997516  Min(alpha.water) = 0.000412357  Max(alpha.water) = 1
  Min(alpha.vapor) = -2.22555e-12  Max(alpha.vapor) = 0.999588
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver:  Solving for T, Initial residual = 4.32478e-05, Final residual = 2.41079e-09, No Iterations 2
min(T) 290.15
GAMG:  Solving for p_rgh, Initial residual = 4.91279e-06, Final residual = 6.3296e-10, No Iterations 3
max(U) 30.2344
min(p_rgh) 1778.9
GAMGPCG:  Solving for p_rgh, Initial residual = 4.09173e-07, Final residual = 3.01626e-10, No Iterations 1
max(U) 29.9168
min(p_rgh) 1779.32
ExecutionTime = 276.17 s


fieldAverage fieldAverage1 output:
    Calculating averages

Courant Number mean: 0.00487556 max: 0.135842
Time = 0.011955

MULES: Solving for alpha.water
Liquid phase volume fraction = 0.997516  Min(alpha.water) = 0.000412479  Max(alpha.water) = 1
  Min(alpha.vapor) = -4.44089e-16  Max(alpha.vapor) = 0.999588
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver:  Solving for T, Initial residual = 4.32198e-05, Final residual = 2.70013e-09, No Iterations 2
min(T) 290.153
GAMG:  Solving for p_rgh, Initial residual = 1.71158e-05, Final residual = 7.83321e-10, No Iterations 4
max(U) 140.097
min(p_rgh) 1138.55
GAMGPCG:  Solving for p_rgh, Initial residual = 1.088e-06, Final residual = 4.13587e-10, No Iterations 2
max(U) 147.712
min(p_rgh) 1226.71
ExecutionTime = 276.46 s

我仔细检查发现很可能是由于求解U方程时，某个网格上面速度突然变得很大，最终导致流场发散，目前想在U方程中或者 P方程中限制最大速度不超过某一个值，由于U是矢量，我现在不太清楚怎么限制流场中的U不超过某一个值呢？是分别限制U某一方向的速度还是直接限制max(mag(U).value)呢？

麻烦哪位前辈能够指点一下呢？谢谢

小考拉

@小考拉

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