I am trying to include a growth model within a convection-diffusion flow. Somehow, I want to introduce new model once the concentration reaches a certain level. Either a mathematical model should be introduced or even the new particles should 'appear' randomly following some form of Boltzmann distribution (this shall be my research...). My two main questions for seasoned LAMMPS users would be:
1) I have been playing around with USER/sph package and managed to implement the Kevin-Helmhotz instability (somewhat, I feel like something ain't very right) here https://goo.gl/WVk7y9. I wonder how hard it would be to add on top the convection-diffusion equation on top? Do I have to write my own LAMMPS package for that?
2) How could I introduce these new 'growing' particle on the surface, either at random or following a model. Which command in LAMMMPS allow that? Apparently I have tried googling "lammps new particle" "lammps random" "lammps grow" but none of the results prove to be useful...