自定义函数求助

[红豆沙]

刚开始top边界条件为zeroGradient，后来改成了symmetry，报以下错误，，请问怎么修改文件呢

--> FOAM FATAL IO ERROR: 

    Cannot find 'value' entry on patch top of field p in file "/home/zc7565/work/yz/mc/0/p"
    which is required to set the values of the generic patch field.
    (Actual type symmetry)

    Please add the 'value' entry to the write function of the user-defined boundary-condition
    or link the boundary-condition into libfoamUtil.so

file: /home/zc7565/work/yz/mc/0/p::boundaryField::top from line 49 to line 49.

    From function genericFvPatchField<Type>::genericFvPatchField(const fvPatch&, const Field<Type>&, const dictionary&)
    in file fields/fvPatchFields/basic/generic/genericFvPatchField.C at line 71.

[红豆沙]

问题 稍微解决，，将symmetry边界换成wall边界，使用zeroGradient 可以算了，，先算 再看