open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I'm using telemac2d to model the transport of algae in a canal. Up until now I've been dropping particles all at once at a given time. I now want to release these particles in packets at a given time interval.

I've started by modifying the fortant user_flot.f file, but I'm getting stuck. Here is the fortant file and the output ASCII file (alf_pos.dat) below.
I think the NaN error is due to TAGFLO because the tags start again at 0 with each packet.

Can you advise this?

Kind regards

Hello,

As told a few times in other posts, if a segmentation fault or a NaN (Not a Number) occurs, you should use a debug configuration with debug options to investigate.
See e.g. the S11.gfortran.debug configuration in the $HOMETEL/configs/systel.edf.cfg configuration file, in particular the flag fflags_debug_gfo for gfortran compiler.
fflags_debug_gfo: -g -Wall -fcheck=all -fbacktrace -fbounds-check -finit-integer=-1 -finit-real=nan -ffpe-trap=invalid,zero,overflow

It will show in which subroutine the issue/nan/segfault occurs, the first suspicious line and may help you to change something in your computation.

Hope this helps,

Chi-Tuan

Hello Pham,

I was able to carry out a number of tests on my own. In my opinion, the user_flot file seems correct. I think that the problem may come from one of the Telemac source files, which would apply the coordinates to the particles.
In particular the oilspill.f file which contains the OIL_DERIVE routine.
However, I can't solve my problem, I get NaNs after the first packet is dropped.
Attached is my current version of the userflot file.

Hello,

I've been able to run a few more tests and upgrade to V8P5. However, I still have the same problem.
Could the cause be the streamline and algae_transp files?
Maybe it's because there's only one ASCII output file? 1 packet of particles = 1 alg_pos.dat file?

If anyone has any clues.

Kind regards

Hello Mathys,

If you do not want to follow my previous advice, it will be difficult to help you.
What I have already suggested will exactly show you in which subroutine or module of the TELEMAC system the Nan or segfault occurs the 1st time. Without this investigation, hard to say more things.

Chi-Tuan