calculating Normal vector in level set method
 

Hi,
If anybody knows level set method help me.
I want to calculate Normal vector (gradient phi)/[gradient phi] in level set method. what kind of discretization should I use? (central differencing or other) .
which one?

Thank you

You have an example of how to calculate the normal vector in the file interfaceProperties.C in which the normal vector is defined in the line:

nHatf_ = nHatfv & Sf;