Dear LAMMPS Users

I want to use AtC package of LAMMPS to study the boiling in porous media using a hybrid MD model that include continuum model (FE) for solid phase of porous media and MD model for liquid and vapor phases around the porous media. I have some questions about this package. Would you please answer them?

1- I read the AtC manual and its related papers and I found that this package just couple MD and FE regions in solids materials not simulation domains that contain solid, liquid and vapor simultaneously. Is AtC package of LAMMPS able to model my problem, i.e., using MD for modeling evaporation and boiling of liquid around the porous matrix and Finite Element method for continuum modeling of porous structure?

2- Whereas the dimensions of solid part of porous medium as well as time domain of simulation are very small, The Fourier heat conduction equation cannot exactly capture the temperature distribution in the porous structure. Therefore, I should use non-Fourier models for heat conduction in solid parts of porous medium such as hyperbolic model or dual phase lag model. Which model does the AtC Package of LAMMPS use for continuum modeling?

3- Does this package by default have the capability of adding temperature dependent source term in the governing equation of continuum model?

4- Using this package can I apply continuum B.Cs like constant heat flux or temperature at the some parts of porous matrix or bottom of computational domain?

Thanks a lot in advance

These are Qs for the AtC folks (CCd)

Steve

Hello Hossein, I have some specific answers, but the current capability will be less stable with fluids. Our current research efforts are linked to improving these capabilities. That said, we have done a few fluids problems, particularly if there is no mass transfer between the finite elemetns and MD. See below for more.

Jeremy

Dear LAMMPS Users

I want to use AtC package of LAMMPS to study the boiling in porous media using a hybrid MD model that include continuum model (FE) for solid phase of porous media and MD model for liquid and vapor phases around the porous media. I have some questions about this package. Would you please answer them?

1- I read the AtC manual and its related papers and I found that this package just couple MD and FE regions in solids materials not simulation domains that contain solid, liquid and vapor simultaneously. Is AtC package of LAMMPS able to model my problem, i.e., using MD for modeling evaporation and boiling of liquid around the porous matrix and Finite Element method for continuum modeling of porous structure?

The AtC release can account for thermal transport problems. If that’s the key aspect, it may be able to model your problem.

2- Whereas the dimensions of solid part of porous medium as well as time domain of simulation are very small, The Fourier heat conduction equation cannot exactly capture the temperature distribution in the porous structure. Therefore, I should use non-Fourier models for heat conduction in solid parts of porous medium such as hyperbolic model or dual phase lag model. Which model does the AtC Package of LAMMPS use for continuum modeling?

We implemented Fourier heat transfer. The code is open source so you can add whatever model you like. The finite element model isn’t tied to a particularly constitutive law.

3- Does this package by default have the capability of adding temperature dependent source term in the governing equation of continuum model?

Yes, you can implement this as an XT_Function.

4- Using this package can I apply continuum B.Cs like constant heat flux or temperature at the some parts of porous matrix or bottom of computational domain?

Yes. See the MSMSE paper by Templeton et al. in 2010 for more information.