N-S方程的求解，基于PETSc工具包，在linux环境下开发的-NS solving equations, based on PETSc toolkit developed under linux environment

This program uses CPP for preprocessing, as indicated by the use of PETSc include files in the directory petsc/include/finclude. This convention enables use of the CPP preprocessor, which allows the use of the #include statements that define PETS