Learning Forum

[annalb21]

I am trying to run a discrete frequency sweep for an antenna simulation in HFSS. The design passes the validation check. When I run the discrete sweep, I first get this warning in the log window:   [warning] Solving frequencies ... (Nondomain solver), process hf3d: Unexpected failure. Then the discrete frequency sweep starts but reports an error saying it failed on each frequency (e.g.  [error] Simulation at frequency '990MHz' failed. ). At the end of the execution it reports the discrete sweep is complete and then the following two errors:  [error] Sweep Sweep failed.  [error] Simulation completed with execution error on server: Local Machine.nOddly, an interpolating sweep seems to run fine (reports no errors and shows reasonable results). What is the cause of the discrete sweep failing and how can I fix it? nErrors reported: n [warning] Solving frequencies ... (Nondomain solver), process hf3d: Unexpected failure (2:34:38 PM Apr 19, 2021)n  [info] A discrete frequency sweep with 61 point(s) has been started using HFSS - Solving Distributed. (2:34:40 PM Apr 19, 2021)n  [error] Simulation at frequency '990MHz' failed. (2:34:40 PM Apr 19, 2021)n  ...n  [error] Simulation at frequency '400MHz' failed. (2:34:41 PM Apr 19, 2021)n  [info] Discrete frequency sweep complete. (2:34:41 PM Apr 19, 2021)n  [error] Sweep Sweep failed (2:34:41 PM Apr 19, 2021)n  [error] Simulation completed with execution error on server: Local Machine. (2:34:41 PM Apr 19, 2021)nnn

[AndyJP]

try resetting HFSS "HPC and Analysis Options" to default, leaving only necessary number of workers/cores. For example, enabling memory distributed option not just allows using memory distribution, but forces the solver to change it's behaviour in non-multithreaded way, always. Other changes in solver's behaviour are also possible. And disable each and every beta option.
Don't forget to manually delete the solutions folder when any such error arises. it is often related to bad data acculumated in solutions.

[annalb21]

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I believe the "HPC and Analysis Options" are set to their defaults. I have never knowingly edited them, but I am not entirely sure what the default values are, so I have attached screenshots. Are these values as expected?

By manually deleting the solutions folder, do you mean deleting the folder on the computer called design_name.aedtresults? I have tried deleting this and rerunning the simulation, but it did not solve the problem.

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[VivekKamble]

Hello Array,
please let us know the version of AEDT you are running. Could you please try running the sweep with a larger frequency step size?
Please let us know if the issue persists with a larger step size.

Regards,
Vivek

[annalb21]

I'm running Ansys EM Suite 2020 R2 (Build 2020-05-28 21:17:40).
The issue persists with a larger step size. Running with frequency step sizes of 10 MHz (original), 50 MHz, and 100 MHz all fail. It is impractical and not useful for the frequencies I simulate at (100 MHz-1GHz) to go above a 100 MHz step size.

[VivekKamble]

HelloArray,
we need to diagnose this issue and not possible to work on this on the forum platform.
To resolve this, you need to get in contact with your local Ansys Support Coordinator/ Account manager, who can forward your query to the Ansys support team.

Regards,
Vivek

[Matt Madore]

Array This is something we’ve seen recently with Temp directories and discrete sweeps. Ensuring there are no spaces or special characters in the temp directory has been the common solution with this issue. By changing your Temp Directory under Tools -> Options -> General Options -> General -> Directories that should resolve the issue.