Partial radiation conditions in finite element analysis of diffraction problem

We develop a program, which can be used for two-dimensional scalar diffraction problems in a domain with complex structure by finite element method with partial radiation conditions. There are many different ways to solve a diffraction problem. They can be classified in two classes. The first one is the reduction of the boundary value problem to an integral equation. The second way is to solve this boundary value problem directly. The most universal method to solve a boundary value problem is the finite element method.