Hi: I'm a physicist with a minor in math, and using PHOENICS has started me wondering about the physical meaning of numerical instability - specifically the higher order differencing schemes applied to laminar flows. Apparently I can actually adjust solution outcomes by changing the degree of instability (i.e., the amount of relaxation necessary to prevent the solutions from "blowing up"). I'm trying to cast this in my thoughts in a valid way - i.e., as analogous physical processes, imaginary material properties, etc. Is there some literature on the subject that I've overlooked?

Thanks, PattiMichelle

Try search on "artificial viscosity".

Ahhh... very interesting! Thanks for the reply. Patti