Abstract: A method of constructing rational interpolating surface under local coordinate systems is presented, which can be used to solve the "large torsion problem" of surfaces. This kind of surface has better approximating effect and its properties can be easily discussed, so it has practical applications not only in CAD but also infinite element analysis and other fields. An example is given in the paper.

Key words: Darcy’s law, Boltzmann equation, Navier-Stokes equation, Chapman-Enskog expansion