Moving heat source problem

LAMMPS LAMMPS Beginners
1

Hello everyone,

I’m currently trying to simulate a moving heat source.

I’ve applied the “fix laser_heating all langevin 100 300 400 654759” code along with the NVE ensemble.

Additionally, I’ve used the command “fix move_laser_region laser_region move linear 0.0 0.01 0.0 units box” to move the heat source along y-direction.

However, I’m encountering the following issues:

a) The temperature is unexpectedly rising beyond 600.

b) Even if I am lowering the thermostat temperature, it does not impact much on the overall temp

c) The heat source doesn’t seem to be moving.

I would greatly appreciate any help in identifying and resolving these problems. Thank you!

2

It would seem to me that applying your thermostat to all atoms is at odds with your desire to heat a specific region.

To paraphrase Sytemantics: Complex systems almost never work. And those that do are built from simple systems that work.

Have you successfully built a simulation where you have defined and heated a specific static region?

1 Like
3

I tried to define it to a specific region, but it does not really make any difference in terms of the system temp

4

It seems that you are trying to solve multiple issues here at once. What is the point of attempting to add a moving heat source if the entire system’s temperature is not under control?

I see that you are getting more traction in a different thread for the same problem. I would highly advise you to follow Dr. Kohlmeyer’s advice given in it.