[Getfem-users] Helmholtz brick and QU term

[Jiří Roleček]

Dear all,
I want to solve Helmholtz problem using standard_complex_model_state, which constists of
2 volume regions
3 surface regions - a) transmitting region, b) reflecting region and c) border region, where i want the waves to pass out of volume
My question is, whether i have all the parameters set well

For the volumes, i use
       getfem::mdbrick_Helmholtz<MODELSTATE> WAVE(mim, mf_u, complex_type(0,0));
and then I set
      WAVE.wave_number().set(convexValuesByRegion);
convexValuesByRegion is a vector of complex values of wave number K

Then I add Robin condition acccording to c) and there I'm really in doubt if I'm right
      // (non-homogeneous) Robin conditions
      getfem::mdbrick_QU_term<MODELSTATE> ROBIN(WAVE, borderValueRobin * complex_type(0,1.), regIndsRobin[0]);
where borderValueRobin is real part of wave number K, which is set in the volume next to this region
(When K in the volume is (400 + 0.5i, then borderValueRobin is 400, so the term in QU_brick is (0 + 400i) - is it right?)

And finally I set the a) and b) region values
  std::vector<double> emitValues(numDOFs, 1);
  getfem::mdbrick_Dirichlet<MODELSTATE> DIRICHLET1(ROBIN,transmittingRegion); 
  DIRICHLET1.rhs().set(mf_data, emitValues);
  DIRICHLET1.set_constraints_type(getfem::constraints_type(PARAM.int_value("DIRICHLET_VERSION")));

  emitValues=std::vector<double> (numDOFs, 0);
  getfem::mdbrick_Dirichlet<MODELSTATE> DIRICHLET2(DIRICHLET1,reflectingRegion); 
  DIRICHLET2.rhs().set(mf_data, emitValues);
  DIRICHLET2.set_constraints_type(getfem::constraints_type(PARAM.int_value("DIRICHLET_VERSION")));


Everything seems to work well, but I think, that there are reflections from the c) region (although its almost perpendicular to the propagating wave), thats why I am asking you to be sure  Iam right or not.

Thank you for your help

Jiri Rolecek