confi999
Junior Member level 3
Hello,
I am doing simulation in ADI-FDTD and time step dt is 'n' times the maximum CFL limit of dt of normal FDTD. So, dt_adi=n*dt_fdtdmax. If I want to match the waveforms of ADI-FDTD and explicit FDTD the waveforms of ADI with dt above the CFL limit needs to be scaled up/ down by a factor of 'n' (this could be 'n^2' or 'sqrt', I am not sure). When I multiply the ADI waveform with 'n' (i.e. scaled up by a factor of 'n') (also multiply by 'n' on time scale or x axis) only then my waveform matches with that of explicit FDTD.
Can anybody give the explanation why this scaling up is required? Also can you please confirm whether the scaling factor should be 'n', 'n^2' or 'sqrt'? And whether it should be scaled down or up??
One hint could be in dt time, energy transferred by the EM wave is = constant*E^y*dt (E is the electric field).
I would highly appreciate if someone correct me in the above and give the (physical) explanation why it is required. Thank you very much.
I am doing simulation in ADI-FDTD and time step dt is 'n' times the maximum CFL limit of dt of normal FDTD. So, dt_adi=n*dt_fdtdmax. If I want to match the waveforms of ADI-FDTD and explicit FDTD the waveforms of ADI with dt above the CFL limit needs to be scaled up/ down by a factor of 'n' (this could be 'n^2' or 'sqrt', I am not sure). When I multiply the ADI waveform with 'n' (i.e. scaled up by a factor of 'n') (also multiply by 'n' on time scale or x axis) only then my waveform matches with that of explicit FDTD.
Can anybody give the explanation why this scaling up is required? Also can you please confirm whether the scaling factor should be 'n', 'n^2' or 'sqrt'? And whether it should be scaled down or up??
One hint could be in dt time, energy transferred by the EM wave is = constant*E^y*dt (E is the electric field).
I would highly appreciate if someone correct me in the above and give the (physical) explanation why it is required. Thank you very much.