floating point exception

七辆战车

如题，出错情况如下，但是和通常情况下的浮点数例外又不太一样，有人知道这个错误是什么原因引起的吗？上一个时间步的库朗数0.87，字典中设置的最大库朗数为0.9，和这个有关系吗？

[2] #0  Foam::error::printStack(Foam::Ostream&) at ??:?
[2] #1  Foam::sigFpe::sigHandler(int) at ??:?
[2] #2  ? in /lib/x86_64-linux-gnu/libc.so.6
[2] #3  Foam::DILUPreconditioner::calcReciprocalD(Foam::Field<double>&, Foam::lduMatrix const&) at ??:?
[2] #4  Foam::DILUPreconditioner::DILUPreconditioner(Foam::lduMatrix::solver const&, Foam::dictionary const&) at ??:?
[2] #5  Foam::lduMatrix::preconditioner::addasymMatrixConstructorToTable<Foam::DILUPreconditioner>::New(Foam::lduMatrix::solver const&, Foam::dictionary const&) at ??:?
[2] #6  Foam::lduMatrix::preconditioner::New(Foam::lduMatrix::solver const&, Foam::dictionary const&) at ??:?
[2] #7  Foam::PBiCGStab::scalarSolve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
[2] #8  Foam::PBiCGStab::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
[2] #9  Foam::fvMatrix<double>::solveSegregated(Foam::dictionary const&) at ??:?
[2] #10  Foam::fvMatrix<double>::solveSegregatedOrCoupled(Foam::dictionary const&) at ??:?
[2] #11  Foam::fvMesh::solve(Foam::fvMatrix<double>&, Foam::dictionary const&) const at ??:?
[2] #12  Foam::SolverPerformance<double> Foam::dynamicOversetFvMesh::solve<double>(Foam::fvMatrix<double>&, Foam::dictionary const&) const at ??:?
[2] #13  Foam::dynamicOversetFvMesh::solve(Foam::fvMatrix<double>&, Foam::dictionary const&) const at ??:?
[2] #14  ? in ~/OpenFOAM/user-v1906/platforms/linux64GccDPInt32Opt/bin/overOlaDyMFlow
[2] #15  __libc_start_main in /lib/x86_64-linux-gnu/libc.so.6
[2] #16  ? in ~/OpenFOAM/user-v1906/platforms/linux64GccDPInt32Opt/bin/overOlaDyMFlow
[zc:02256] *** Process received signal ***
[zc:02256] Signal: Floating point exception (8)
[zc:02256] Signal code:  (-6)
[zc:02256] Failing at address: 0x3e8000008d0
[zc:02256] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x3ef20)[0x7fdf3dd29f20]
[zc:02256] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0xc7)[0x7fdf3dd29e97]
[zc:02256] [ 2] /lib/x86_64-linux-gnu/libc.so.6(+0x3ef20)[0x7fdf3dd29f20]
[zc:02256] [ 3] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam18DILUPreconditioner15calcReciprocalDERNS_5FieldIdEERKNS_9lduMatrixE+0xa5)[0x7fdf3f197095]
[zc:02256] [ 4] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam18DILUPreconditionerC1ERKNS_9lduMatrix6solverERKNS_10dictionaryE+0xa4)[0x7fdf3f197224]
[zc:02256] [ 5] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam9lduMatrix14preconditioner31addasymMatrixConstructorToTableINS_18DILUPreconditionerEE3NewERKNS0_6solverERKNS_10dictionaryE+0x2e)[0x7fdf3f1973ae]
[zc:02256] [ 6] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZN4Foam9lduMatrix14preconditioner3NewERKNS0_6solverERKNS_10dictionaryE+0x917)[0x7fdf3f17e637]
[zc:02256] [ 7] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZNK4Foam9PBiCGStab11scalarSolveERNS_5FieldIdEERKS2_h+0x8df)[0x7fdf3f18a53f]
[zc:02256] [ 8] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so(_ZNK4Foam9PBiCGStab5solveERNS_5FieldIdEERKS2_h+0x53)[0x7fdf3f18cc53]
[zc:02256] [ 9] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE15solveSegregatedERKNS_10dictionaryE+0x187)[0x7fdf43a49c47]
[zc:02256] [10] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZN4Foam8fvMatrixIdE24solveSegregatedOrCoupledERKNS_10dictionaryE+0x3a5)[0x7fdf4357d895]
[zc:02256] [11] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so(_ZNK4Foam6fvMesh5solveERNS_8fvMatrixIdEERKNS_10dictionaryE+0x23)[0x7fdf43521553]
[zc:02256] [12] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/liboverset.so(_ZNK4Foam20dynamicOversetFvMesh5solveIdEENS_17SolverPerformanceIT_EERNS_8fvMatrixIS3_EERKNS_10dictionaryE+0x2d2)[0x7fdf3ff4fee2]
[zc:02256] [13] /home/user/OpenFOAM/OpenFOAM-v1906/platforms/linux64GccDPInt32Opt/lib/liboverset.so(_ZNK4Foam20dynamicOversetFvMesh5solveERNS_8fvMatrixIdEERKNS_10dictionaryE+0x1d)[0x7fdf3ff5076d]
[zc:02256] [14] overOlaDyMFlow(+0x57c8c)[0x55bfc0ab9c8c]
[zc:02256] [15] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe7)[0x7fdf3dd0cb97]
[zc:02256] [16] overOlaDyMFlow(+0x6b36a)[0x55bfc0acd36a]
[zc:02256] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 2 with PID 0 on node zc exited on signal 8 (Floating point exception).
user@zc:~/OpenFOAM/OpenFOAM-v1906/run/various/floatingObject_refined/background$ ^C
user@zc:~/OpenFOAM/OpenFOAM-v1906/run/various/floatingObject_refined/background$

李东岳

好像矩阵奇异，什么求解器？

七辆战车

@东岳用的overOlaDyMFlow，但是都已经跑了快四个周期才出的这问题

五好青年

@七辆战车
我跟你是同样的报错，你后来咋解决的呢
感谢

Tong

@五好青年

DILU 预条件器出错对应代码在

DILUPreconditioner.C 90行

     for (label cell=0; cell<nCells; cell++)
     {
 90        rDPtr[cell] = 1.0/rDPtr[cell];
     }

更换预条件器换成diagonal或者none一般就可以，或者换光顺求解器也可以。
一般不完全ILU分解做预条件器，是不能够完全分解成一个L和U矩阵的，还会剩下一个对角阵D，如果某行完全分解了，那么对角阵会有元素为0，由于这第90行代码会将D中的元素做除数，OpenFoam刚好又会捕捉浮点数异常，程序就退出了。

zhou

@Tong 大佬能教一下具体的操作步骤吗，我刚学openfoam不知道应该怎么去操作

CFD中文网

floating point exception