tran quyet thang <hereiam2005@...> writes: > > > Dear professor Johnson and Meep users, > > It has been mentioned multiple times that a capacity similar to variable mesh size can be emulated in meep by applying the coordinate transformation technique formulated in "Coordinate Transformation & > Invariance in Electromagnetism". > > However my attempts in applying the technique to a scaling factor larger than one always resulted in field divergence. > > This script tried to scale the whole computation domain, filled with air, by a factor of 2 in all directions. According to the article, that would corresponds into an s factor of 2, or an epsilon and mu of > 0.5. > > > > (set-param! resolution 200) (define-param fcen 1.0) (define-param df 1.0) (set! geometry-lattice (make lattice (size 0.2 0.2 0.2))) ;(set! pml-layers (list (make pml (thickness 0.5)))) (set! geometry (list > (make block (center 0 0 0) (size infinity infinity infinity) (material (make dielectric (epsilon 0.5) (mu 0.5) ))))) (set! sources (list (make source (src (make gaussian-src (frequency fcen) (fwidth df)) ) (component Ez) (center 0 0 0) )))(define (field-Ez) (print "Field:" (get-field-point Ez (vector3 0 0 0)) "\n")) (run-until 100 ;(after-sources > (at-every 0.1 field-Ez) ;)) > > > Field however quickly diverges. > > Any attempt to stretch the coordinates would involve stretching the air surrounding the devices, which will make the field diverge. > > Could anyone provide assistance? Thank you so much.Yours sincerely, Tran Quyet Thang.Ajou University. > > > > _______________________________________________ > meep-discuss mailing list > meep-discuss@... > http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
Hi everyone, A quick update: a lower Courant factor - corresponds to the stability condition - and the field no longer diverges. Thanks everyone! Hopefully this would be useful to future Meep users! Best regards. _______________________________________________ meep-discuss mailing list meep-discuss@ab-initio.mit.edu http://ab-initio.mit.edu/cgi-bin/mailman/listinfo/meep-discuss
