Question regarding conductivity implementation in code
pingpongballz opened this issue · comments
Hi,
I was browsing through objects.py
when I came upon this, lines 192-199,
self.absorption_factor = (
0.5
* self.grid.courant_number
* self.inverse_permittivity
* self.conductivity
* self.grid.grid_spacing
/ const.eps0
)
which is f = 0.5*sc*inv(ε)*σe*du/ε0
In https://github.com/flaport/fdtd#lossy-medium, the following is written:
f = 0.5*dt*σ, where σ := inv(ε)*σe/ε0
by taking dt = sc * du/c
I can expand f = (0.5*sc*inv(ε)*σe*du)/(ε0*c)
My question is, why wasn't 1/speed of light, 1/c
included in self.absorption_factor
? There must be something I'm missing, right?
Any clarification to my confusion would be most appreciated 😄
Hi @pingpongballz ,
My apologies for my very late answer. I wanted to re-derive the equations and then forgot about this issue. It seems you are indeed correct! There is a 1/c factor missing. I have updated the code and the README.