T8a:
Heat transport:
equilibration
Before the tutorials:
Think about:
- What does heat transport mean?
- What happens when two fluids with different temperatures are in contact?
- How can you demonstrate that conduction is an irreversible process?
During the tutorials:
To run the experiment, we first need to
- Use the 200×10×10 setup of T06 to check the equilibration by heat transport of a slab with two different temperatures at its ends.
- Mark all particles as boundary particles (i.e., set their
ID to zero), so that they don’t move.
(Don’t forget to set SPH_BND_PARTICLES in the Config.sh file when compiling the code.)
- Give one side a 5 higher temperature.
- When compiling the code, switch on
CONDUCTION and CONDUCTION_CONSTANT and SPH_BND_PARTICLES_ALLOW_CONDUCTION in the Config.sh file.
- Add
ConductionEfficiency 0.2 and MaxSizeConductionStep 0.05 to the parameter file.
- Look at the evolution of the internal energy and explain what happens.
- Try to plot the entropy and see what happens.
Programming goals for T8:
Improve your ability to set up special geometries in the initial conditions.
Solutions
- Again, extending the setup script from T06 for the first test problem.
- To look at the evolution of the internal energy.
you should get something like shown below
- Example using Fortran and gnuplot:
ifx -g -traceback -check all -fpe0 -o slabsetup slabsetup.f90
(this uses glass.txt from T04)
./slabsetup
gnuplot grid.plt (to check that the particle positions are set up correctly)
- compile Gadget with
PERIODIC and NOGRAVITY and SPH_BND_PARTICLES
and with LONG_X=10, LONG_Y=1, and LONG_Z=1.
- run Gadget using
slab.ic as the initial conditions file
and BoxSize = 1
in the parameter file
(and TimeMax = 100, TimeBetSnapshot = 0.1, and ConductionEfficiency = 10)
ifx -g -traceback -check all -fpe0 -o readsnap readsnap.f90
for file in snap_???; do ./readsnap $file >$file.txt; done
gnuplot slab.plt
(this requires ffmpeg, which is installed on the mpusm06 machine)
xine -l slab.mp4
