# How to simulate a process of convective heat transfer?

Excuse me,I would like to simulate a convective heat transfer process.However,factors like temperature,pressure,energy are all in the change in the fluid flow process.It is unreasonable to choose ensembles of nve,nvt,npt etc.What Lammps command can help me fulfill this simulation?Thank you!
Youwei

please be aware that restating the same question over and over again
(presumably, because you don't like the answers you were given) is not
considered good mailing list etiquette. if you don't like the answers,
perhaps you should ask a different (better!) question.

Excuse me,I would like to simulate a convective heat transfer

convective heat transfer for what kind of system? made out of what
kind of particles? at what dimensions? with what boundary conditions?
using what model/theory?

your question is too general. like somebody going to a car dealing an
saying: i want a red car.

process.However,factors like temperature,pressure,energy are all in the
change in the fluid flow process.It is unreasonable to choose ensembles of
nve,nvt,npt etc.What Lammps command can help me fulfill this
simulation?Thank you!

your question is backwards. *you* have to find out what is the
theory/model/potential/boundary conditions that is suitable for
performing the simulation that you want to do. once you have figured
out the physics, *then* you can look at which features in LAMMPS are
available to realize this. it looks a lot that you should have a long
chat with your adviser first. a mailing list is no replacement for
that and will not solve the problems that are essentially your
problems.

axel.

How large is the convective boundary layer thickness in your problem?

2013/11/6 下午8:08 於 “youwei” <[email protected]…127…> 寫道：

I simulate a flow in a nanochannel consisted of two infinite plates.The channel height is 12nm ,convective boundary layer thickness is rather tiny.Could you give me some suggestions about ensemble choice？

If water is your medium fluid, then 12 nm is quite small. A rule of thumb, water-water separation is approximately 3A, so there is about 40 layers of water in between. If my memory is correct, surface boundary effect diminishes at 10 layers of water, so probably you only have 20 layers of bulk like water.
I have not done a lit rev, but I bet there is plenty of papers talking about the shear viscosity in a system like this. Maybe you can start from learning their approaches. Also, is it natural or forced convection? The concept of boundary layer is questionable for a characteristic length this small.

LC Liu

2013/11/6 下午8:33 於 “youwei” <[email protected]…3114…> 寫道：

Thank you!I choose Supercritical fluid-Argon.The flow is through forced convection.