| Author | Message | ||
     Mahir Celik (mahir) Member Username: mahir Post Number: 5 Registered: 06-2003 |
Hello Mr. Nelson, this is my Equation EQUATIONS div(-K*grad(Vr))-div(Eps*omega*grad(Vi))=0 div(-K*grad(Vi))+div(Eps*omega*grad(Vr))=0 i want to define a Natural(Vr) and Natural(Vi) for current densinty at the boundary. But I've to multiply natural(Vi) and natural(Vr) with the same factor as in the Equation. Have I to multiply natural(Vr) by K or by (K+Eps*omega)? | ||
| Robert G. Nelson (rgnelson) Moderator Username: rgnelson Post Number: 28 Registered: 06-2003 |
As described in the help sections on Natural Boundary Conditions, FlexPDE integrates all second-order terms by parts, generating surface integral terms. These surface integral terms are given a value by the Natural() boundary condition statement. In your case, both div(-k*grad(Vr)) and -div(Eps*omega*grad(Vi)) in the first equation are second order, and will be integrated by parts. So the meaning of the Natural() BC for this equation is the outward normal component of -K*grad(Vr)-Eps*omega*grad(Vi). The treatment of the second equation will result in similar terms. |