Gray-Scott Model at F 0.0300, k 0.0710  

These images and movie demonstrate the behavior of the Gray-Scott reaction-diffusion system with σ=Du/Dv=2 and parameters F=0.0300, k=0.0710.

These parameter values create "doomed" pulsar solitons that very closely resemble the viable solitons that arise just a bit to the west and north, before dying out. This one starts its final growing pulse 4400 tu after creation. The period (178 tu) is very close to that of other pulsar solitons in this region of the parameter space.

The eastern limit for solitons at F=0.0300 is about k=0.0707.

Categories: Pearson R; Wolfram 1    (glossary of terms)

             increase F









      
decrease k
      
after 60 tu
after 300 tu

15 frames/sec.; each fr. is 20 iter. steps = 10 tu; 607 fr. total (6,070 tu)









      

      
after 1,100 tu after 4,500 tu
                
(Click on any image to magnify)

In these images:

Wavefronts and other moving objects have decreasing u values (brighter color) on the leading edge of the blue part of the moving object, and increasing u (light pastel color) on the trailing edge. This is true even for very slow-moving objects — thus, you can tell from the coloring what direction things are moving in.

''tu'' is the dimensionless unit of time, and ''lu'' the dimensionless unit of length, implicit in the equations that define the reaction-diffusion model. The grids for these simulations use Δx=1/143 lu and Δt=1/2 tu; the system is 3.2 lu wide. The simulation meets itself at the edges (periodic boundary condition); all images tile seamlessly if used as wallpaper.

Go back to Gray-Scott pattern index


Robert Munafo's home pages on HostMDS   © 1996-2017 Robert P. Munafo.
aboutcontact    mrob    mrob27    @mrob_27    mrob27
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. Details here.

This page was written in the "embarrassingly readable" markup language RHTF, and was last updated on 2017 Feb 02. s.11