[WUJT]

Hi Everyone，
When I run my cvg， It stopped as follows：

reading inputs.in data from file inputs.in
reading engine.in data from file engine.in
reading amr.in data from file amr.in
turb_flag = 1 in inputs.in, reading in turbulence.in
reading turbulence.in data from file turbulence.in
reading mech.dat data from file mech.dat
reading species.in data from file species.in
trying to read in therm.dat... reading
there are 325 reactions and 53 species
reading initialize.in data from file initialize.in
reading gas.dat data from file gas.dat
reading boundary.in data from file boundary.in
generating a piston profile from the inputs in engine.in
file name exhaust_lift.in given for velocity boundary condition
reading exhaust_lift.in data from file exhaust_lift.in
file name exhaust_lift.in given for velocity boundary condition
reading exhaust_lift.in data from file exhaust_lift.in
file name intake_lift.in given for velocity boundary condition
reading intake_lift.in data from file intake_lift.in
file name intake_lift.in given for velocity boundary condition
reading intake_lift.in data from file intake_lift.in
file name intake_lift.in given for velocity boundary condition
reading intake_lift.in data from file intake_lift.in
reading events.in data from file events.in
reading post.in data from file post.in
reading surface.dat data from file surface.dat
creating disconnect triangles for concentric circles between regions 0 and 1
creating disconnect triangles for concentric circles between regions 0 and 1
creating disconnect triangles for concentric circles between regions 0 and 2
creating disconnect triangles for concentric circles between regions 0 and 2
reading embedded.in data from file embedded.in
CLOSING EVENT: activating triangles in a disconnect group between regions 0 and 1
CLOSING EVENT: activating triangles in a disconnect group between regions 0 and 1
CLOSING EVENT: activating triangles in a disconnect group between regions 0 and 2
CLOSING EVENT: activating triangles in a disconnect group between regions 0 and 2
OPENING EVENT: deactivating triangles in a disconnect group between regions 0 and 1
OPENING EVENT: deactivating triangles in a disconnect group between regions 0 and 1
The parallel block size (dx, dy, dz) is 1.920000e-001 1.920000e-001 1.920000e-001.

[ksrivast]

Hello Wu,

Please check to see if you have a signal 9 error when the program terminates. If so, you might be running out of memory. You can either run on nodes with higher memory capacity or increase your base grid sizes, for starters.

Hope this helps.

Sincerely,

Srivastava

[WUJT]

Hello Srivastava,
What’s the means of “signal 9 error” ? My computer’s memory is 64 GB. And its base grid sizes is 0.003. I think it may be not due to the memory. The echo files of engine, installation, events, and so on are only 0kb. What ‘s wrong with it ? Can I send it to your email?

Thanks

[ksrivast]

Hello Wu,

When a process exits on signal 9, it points to it not having enough memory to run on. Please check what message you are being provided in your terminal when the process terminates. I need to know why your process was killed. For example, you might get something similar to this :
mpirun noticed that process rank 0 exited on signal 9 (Killed).

What's your estimated cell count? You can use STUDIO to figure this out. Please make sure it is reasonable. Try a higher negative value for parallel_scale in inputs.in to see if that helps (-3 or -4).

Sincerely,

Srivastava

[WUJT]

Originally Posted by ksrivast

Hello Wu,

When a process exits on signal 9, it points to it not having enough memory to run on. Please check what message you are being provided in your terminal when the process terminates. I need to know why your process was killed. For example, you might get something similar to this :
mpirun noticed that process rank 0 exited on signal 9 (Killed).

What's your estimated cell count? You can use STUDIO to figure this out. Please make sure it is reasonable. Try a higher negative value for parallel_scale in inputs.in to see if that helps (-3 or -4).

Sincerely,

Srivastava

Hi Srivastava，

when I uesd the GRID ESTIMATOR, target cell count 100000, suggested base grid size dx, dy, and dz is 0.00251m. So I think my cell count is about 100000, and my base grid size is 0.003m.

when I use mpirun, it said as follow,

job aborted:
rank: node: exit code[: error message]
0: CFD: -1073741819: process 0 exited without calling finalize
1: CFD: -1073741819: process 1 exited without calling finalize
2: CFD: -1073741819: process 2 exited without calling finalize
3: CFD: -1073741819: process 3 exited without calling finalize
4: CFD: -1073741819: process 4 exited without calling finalize
5: CFD: -1073741819: process 5 exited without calling finalize
6: CFD: -1073741819: process 6 exited without calling finalize
7: CFD: -1073741819: process 7 exited without calling finalize

so i dont know how to explain. By the way, I use base grid size as 0.05m, and it was killed, too.

Thanks

Wu

[ksrivast]

Hello Wu,

Is this a new error, or does it come along with what you had mentioned in the first post? Try higher negative values for parallel_scale in inputs.in to see if that helps. Also, it would be helpful if you can monitor the memory utilization of your processors while the process is running to make certain you're not exceeding the limits/having sudden memory spikes.

If the above doesn't fix your issue, please let us have a look at your case setup. You can send your case files (*.in and *.dat files) to support@convergecfd.com . Please use your official email for all correspondence with Convergent Science. Please mention the issues you are facing and add my name as reference.

Sincerely,

Srivastava

[WUJT]

Hi Srivastava,

This was another error. I had solved the error. It was because I didn't input the compression ratio and move to BDC, and the DOS was killed unnormally. I think there should be some messages, if I forget input the compression ratio.

Thanks very much,

WuJT

[MFGT]

Yes, usually it simply crashes without more notification if surface triangles makes contact with each other (valves hit piston, move into wrong direction, etc.) or if the normals are pointing into the wrong direction.

If there is no information, these are usually the points to look at.

[ksrivast]

Hello Wu,

The compression ratio calculator is just a check to see whether your geometry represents the compression ratio you expect/desire. The target value you enter in Compression Ratio calculation dock in STUDIO shouldn't influence your run in any way.

The problem you experienced could be that your piston was not placed at BDC in your surface.dat geometry file. This is a requirement in CONVERGE. If you use CONVERGE to automatically calculate piston motion using provided engine parameters, CONVERGE will assume the piston boundary is at BDC in the surface.dat file. If your piston was not at the right location in your geometry before, then depending on your stroke, it might have been intersecting with the head/valves, leading to intersections and consequently a crash.

Tobias is right, in that at times CONVERGE crashes without any notifications if it encounters intersections during run. A good way to ensure you have no intersections while your boundary is moving, is to utilize the Animation feature in View Options dock in STUDIO, and enable Check triangle intersection in each step. This would help you verify the motion of the boundaries and ensure no intersections would arise during run.

Sincerely,

Srivastava