各位好
仿照kinematiccloud中的函数Dij，写了一个新的函数Sum，用来计算当前时间步流场中所有粒子的某个属性之和（如直径之和）。
那么如果我想用DPMFoam求解器，并且想在最终的结果文件中将新添加的函数Sum的计算结果输出出来，应该怎么做呢？
这个函数输出的值应该算作粒子属性还是场的属性呢？
谢谢各位！

@星星星星晴 老师我最近开始做本科毕设了，非常感谢您的帮助和耐心讲解。后面可能还有知识要请教您，万分感谢！

@星星星星晴 谢谢老师的耐心讲解！:xinxin:

@星星星星晴 好的，感谢您的指点！

@xpqiu

PATH=/usr/lib64/openmpi/bin:/home/xry/OpenFOAM/xry-2112/platforms/linux64GccDPInt32Opt/bin:/usr/lib/openfoam/openfoam2112/site/2112/platforms/linux64GccDPInt32Opt/bin:/usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/bin:/usr/lib/openfoam/openfoam2112/bin:/usr/java/jre1.8.0_151/bin:/opt/tsce4/maui/sbin:/opt/tsce4/maui/bin:/opt/tsce4/torque6/bin:/opt/tsce4/torque6/sbin:/usr/local/bin:/opt/software/openmpi/bin:/usr/mpich/bin:/usr/bin:/usr/local/sbin:/usr/sbin:.:/home/xry/.local/bin:/home/xry/bin LD_LIBRARY_PATH=/home/xry/OpenFOAM/xry-2112/platforms/linux64GccDPInt32Opt/lib:/usr/lib/openfoam/openfoam2112/site/2112/platforms/linux64GccDPInt32Opt/lib:/usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/sys-openmpi:/usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib:/usr/lib/openfoam/openfoam2112/ThirdParty/platforms/linux64GccDPInt32/lib/sys-openmpi:/usr/lib/openfoam/openfoam2112/ThirdParty/platforms/linux64GccDPInt32/lib:/usr/lib64/openmpi/lib:/usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/dummy:/opt/software/openmpi/lib:/software/openmpi/lib:/usr/mpich/lib:/usr/local/mpc/lib:/usr/local/gmp/lib:/usr/local/mpfr-4.1.0/lib linux-vdso.so.1 => (0x00007ffce15f4000) libfiniteVolume.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libfiniteVolume.so (0x00007faff29f9000) libfvOptions.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libfvOptions.so (0x00007faff2583000) libmeshTools.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libmeshTools.so (0x00007faff1c79000) libsampling.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libsampling.so (0x00007faff1568000) libdynamicFvMesh.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libdynamicFvMesh.so (0x00007faff12ad000) libincompressibleTransportModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libincompressibleTransportModels.so (0x00007faff101a000) libinterfaceProperties.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libinterfaceProperties.so (0x00007faff0d9c000) libimmiscibleIncompressibleTwoPhaseMixture.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libimmiscibleIncompressibleTwoPhaseMixture.so (0x00007faff0b91000) libturbulenceModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libturbulenceModels.so (0x00007faff073a000) libincompressibleTurbulenceModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libincompressibleTurbulenceModels.so (0x00007faff02a7000) libwaveModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libwaveModels.so (0x00007fafeffd5000) libVoFphaseTurbulentTransportModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libVoFphaseTurbulentTransportModels.so (0x00007fafefc15000) libincompressibleInterPhaseTransportModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libincompressibleInterPhaseTransportModels.so (0x00007fafefa12000) libOpenFOAM.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libOpenFOAM.so (0x00007fafeeca9000) libdl.so.2 => /lib64/libdl.so.2 (0x00007fafeeaa5000) libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007fafee79d000) libm.so.6 => /lib64/libm.so.6 (0x00007fafee49b000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007fafee285000) libpthread.so.0 => /lib64/libpthread.so.0 (0x00007fafee069000) libc.so.6 => /lib64/libc.so.6 (0x00007fafedc9c000) libPstream.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/sys-openmpi/libPstream.so (0x00007fafeda81000) libfileFormats.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libfileFormats.so (0x00007fafed6c5000) libsurfMesh.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libsurfMesh.so (0x00007fafed287000) libfluidThermophysicalModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libfluidThermophysicalModels.so (0x00007fafecac0000) libsolidThermo.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libsolidThermo.so (0x00007fafec7c2000) libcompressibleTurbulenceModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libcompressibleTurbulenceModels.so (0x00007fafec2eb000) libdynamicMesh.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libdynamicMesh.so (0x00007fafebbc5000) liblagrangian.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/liblagrangian.so (0x00007fafeb980000) libtwoPhaseMixture.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libtwoPhaseMixture.so (0x00007fafeb766000) libtwoPhaseProperties.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libtwoPhaseProperties.so (0x00007fafeb519000) libspecie.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libspecie.so (0x00007fafeaea1000) libz.so.1 => /lib64/libz.so.1 (0x00007fafeac8b000) /lib64/ld-linux-x86-64.so.2 (0x00007faff511c000) libmpi.so.12 => /usr/lib64/openmpi/lib/libmpi.so.12 (0x00007fafea9a7000) libcompressibleTransportModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libcompressibleTransportModels.so (0x00007fafea7a3000) libthermophysicalProperties.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libthermophysicalProperties.so (0x00007fafea466000) libsolidSpecie.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libsolidSpecie.so (0x00007fafea234000) libreactionThermophysicalModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libreactionThermophysicalModels.so (0x00007fafe940c000) libradiationModels.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libradiationModels.so (0x00007fafe9052000) libextrudeModel.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libextrudeModel.so (0x00007fafe8e22000) libopen-rte.so.12 => /usr/lib64/openmpi/lib/libopen-rte.so.12 (0x00007fafe8ba6000) libopen-pal.so.13 => /usr/lib64/openmpi/lib/libopen-pal.so.13 (0x00007fafe8902000) librt.so.1 => /lib64/librt.so.1 (0x00007fafe86fa000) libutil.so.1 => /lib64/libutil.so.1 (0x00007fafe84f7000) libhwloc.so.5 => /lib64/libhwloc.so.5 (0x00007fafe82ba000) libSLGThermo.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libSLGThermo.so (0x00007fafe80b2000) libdistributed.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libdistributed.so (0x00007fafe7e37000) libblockMesh.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libblockMesh.so (0x00007fafe7b93000) libnuma.so.1 => /lib64/libnuma.so.1 (0x00007fafe7987000) libltdl.so.7 => /lib64/libltdl.so.7 (0x00007fafe777d000) libdecompositionMethods.so => /usr/lib/openfoam/openfoam2112/platforms/linux64GccDPInt32Opt/lib/libdecompositionMethods.so (0x00007fafe74ec000)

@星星星星晴 非常感谢！

@bestucan 在 请问如何理解这一项？ 中说：

我猜是任意方向的加速度。

速度本身是矢量，做梯度就是个二阶张量了，前后乘以n和n的转置，应该是类似于对角化操作（基于某方向的对角化）。把各方向的加速度解耦出来，使之不在其他方向有分量。

这个“任意方向”就是右边那项分母上n的方向，咦，n就是法向哈:chouchou:

那应该就是了

但是要注意右边那项分子，速度有下标的，应该是n方向上的速度。
那这一项的意义应该是：“n方向上的速度，在n方向的加速度”

这也和左边对角化操作印证，嗯，就这么猜:xiezuoye:

理解了，这项应该是一个标量，即“沿自由表面法向的加速度”。

我水平有限，还是需要多研究。

非常感谢您的不吝赐教！

刚听说open foam被esi收购了？

@李东岳 谢谢李老师

@xpqiu 牛，谢谢老兄，:146:

他可能要根据 1000-1500 确认 1000 没出错，能用:chigua2:

可以写个 bash 脚本，里面依序写上你要进行的任务：

计算 修改controlDict 计算 修改controlDict

可以写个循环，修改 controlDict 可以用 sed，查找 startTime 0， 替换。

@李东岳
好的，我试试。感谢回复:146:

@miss-zhou_dut 哎哟我勒个去 :143:

@李东岳 谢谢李老师😄

@李东岳 请问老师，可以实现计算一定步数后，时间步倒退，重新计算一遍嘛？我想尝试计算1000时间步，然后从第500步计算到1500步，再从第1000步计算到2000步，这样可以实现嘛？

@李东岳 李老师，再请教一个问题，在检查网格的时候，cell zones 和 Number of regions的数目必须一样吗？如果不一样的话，请问代表什么问题？

求助各位老师，我试着在sixDoFRigidBodyMotion库中建立一个新的mylinearSpring文件夹（类似于原linearSpring），意图改动其中的锚点anchor的位置。先试着让它z坐标加1，在编译时出错，错误信息如下。

sixDoFRigidBodyMotion/restraints/mylinearSpring/mylinearSpring.C:error: assignment of read-only location ‘((const Foam::sixDoFRigidBodyMotionRestraints::mylinearSpring*)this)->Foam::sixDoFRigidBodyMotionRestraints::mylinearSpring::anchor_.Foam::Vector<Cmpt>::z<double>()’ anchor_.z()=anchor_.z()+1;

提示在给只读位置幅值，是不是意味着在这里anchor是不能变动的量，那要怎样才能改动它呢？

@李东岳 我试了一下，可以的，是我想要的结果。谢谢东岳老师！

@leeck Q562658790

@李东岳 懂了，谢谢李老师