[Getdp] result all zero
Lin Ji
jil at rpi.edu
Fri Oct 26 19:31:03 CEST 2001
Hi, Christophe,
I am not trying to solve the original wave equation in frequency domain.
I am solving the Helmholtz equation
u_xx + u_yy + (\tau^2 / c^2)u = 0
directly where the subscript _xx denotes the 2nd partial derivative to x and
\tau corresponds to a specific frequency. I had the following formulation for
the above equation:
Formulation {
{ Name hhltz; Type FemEquation;
Quantity {
{ Name u; Type Local; NameOfSpace Hgrad; }
}
Equation {
Galerkin { [ tau_c*tau_c/mu[] * Dof{u} , {u} ];
In Omega; Integration I1; Jacobian JVol; }
Galerkin { [ -Dof{d u} , {d u} ];
In Omega; Integration I1; Jacobian JVol; }
Galerkin { [ f_bc[] , {u} ];
In Gamma_f; Integration I1; Jacobian JSur; }
}
}
}
where mu[] = c^2 and tau_c denotes the central frequency and f_bc[] is the
Neumann boundary condition. They are all defined in the Function object.
Thank you for your work and also thank Andre Nicolet for referring the
website.
Lin Ji
--
Dept. of Math., RPI
518-276,6904 (work)