hi every one…
i have 3 question about flow simulation with lammps:
- how can i definition a group of molecule as flow in my code? on the other hand i want to understand that lammps how recognize this group is flow or that group is wall?
- when every one want to simulate nanofluid with lammps how he can definition water group and nanoparticle group together as flow and nanoparticle’s stay rigid?
- can we use ave/spatial command for calculate for example velocity or density/mass of nanofluid flow acroos a channel?
hi every one..
i have 3 question about flow simulation with lammps:
1. how can i definition a group of molecule as flow in my code? on the
other hand i want to understand that lammps how recognize this group is
flow or that group is wall?
Groups can be defined by region, type, id, molecule, or by the dyanamic
command. Groups can be added or subtracted from each other, so your group
flow can be composed of group water and group nanoparticle. Please see
group doc page for more details.
2. when every one want to simulate nanofluid with lammps how he can
definition water group and nanoparticle group together as flow and
nanoparticle's stay rigid?
You can use the fix rigid family to keep the nanoparticle rigid while
flowing.
3. can we use ave/spatial command for calculate for example velocity or
density/mass of nanofluid flow acroos a channel?
Yes, certainly.
Ray
tanks dear ray shan..
1. i do this but i want to know how lammps recognize this group (water
and nanoparticle) as flow?
You tell LAMMPS that water and nanoparticles belong to a group called
flow. E.g. "group flow union water nanoparticle"
2. i use read data command, can i use fix rigid family?
Of course.
3. okey but i want use ave/spatial for calculate density of nanofluid flow
and nanofluid have a different formula for account density by using volume
fraction of nanoparticle.. is this correct?
Sorry but this is not a LAMMPS question. Talk to your colleagues and/or
advisor.
Ray
Sorry but this is not a LAMMPS question. Talk to your colleagues and/or
advisor.
i want to know how lammps account density/number or density/mass of one
group..? what is formula?
the formula is "sum of computed items in volume per volume". what else?
what ave/spatial does is described in its documentation:
that has everything you will need unless you want to know the
technical implementation details. for that you have to read the source
code. there is nothing fancy there. all you need is a little common
sense and the willpower to think for yourself.
axel.