The Gray-Scott Reaction Diffusion Model displays the spatial concentration of chemical species U and V under the influence of the reaction U+2V->3V and V->P.  The simulation models this reaction in an open system with a constant addition of U and removal of V due to a flow rate f and with the removal of V by the reaction V->P with reaction rate k.  Combining this autocatalytic process with diffusion results in pattern formation that depends on the f and k rates and on the U and V diffusivities Du and Dv.  This reaction diffusion system has a surprising variety of spatiotemporal patterns when starting in the initial state U=1 and V=0 except for a square grid at the center where U=1/2 and V=1/4.  

The Gray-Scott Reaction Diffusion Model was developed using the Easy Java Simulations (EJS) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.   Double clicking the jar file will run the program if Java is installed.  You can modify this simulation if you have EJS installed by right-clicking within the map and selecting "Open Ejs Model" from the pop-up menu item.

Please note that this resource requires at least version 1.6 of Java (JRE).