Tagged: error-code, fdtd, Lumerical-FDTD
January 6, 2022 at 6:26 amejlee0911Subscriber
I have to simulate optical cavities with a dipole source. When I set LC attribution for the bottom, a problem showed up.
I got this message below.January 8, 2022 at 1:38 amKyleAnsys Employee
It's possible that the memory could be the cause of this crash, even if the available memory is larger than the estimate. Can you try reducing the memory requirement of the simulation by removing monitors, reducing the number of mesh points or the span of the simulation, reducing the number of frequency points being recorded, etc. then running it again?
January 25, 2022 at 5:07 amejlee0911Subscriber
Thank you, kjohnson. I had tried the lists you recommended. And I had reduced the memory, especially doing the span of the simulation.
I have some questions about PML type.
I thought it was still used much time when the structure is a simple cavity (only metal-insulator-metal).
I used a dipole source with a single wavelength and the dipole source is in the insulator. For simulation, I increase the simulation time (20000 fs) and reduce the auto shutoff min (5e-05). And doing the convergence test, I found the number of PML layers must be 42 at least because the alpha value is not 0. If alpha was set 0, simulation diverged. For simulation optimization, I changed the PML type. For associated files in some Lumerical support-articles (examples in circular polarization and phase convention (https://support.lumerical.com/hc/en-us/articles/1500006150981-Circular-polarization-and-phase-convention) and understanding dipoles in non-homogeneous materials (https://support.lumerical.com/hc/en-us/articles/360034382834-Understanding-dipoles-in-non-homogeneous-materials)) use the uniaxial anisotropic PML. I apply this PML type to my simulation. Using this type I got the results much faster than stretched coordinate PML. But in information (https://support.lumerical.com/hc/en-us/articles/360034382674-PML-boundary-conditions-in-FDTD-and-MODE), a legacy uniaxial anisotropic PML seems not to recommend. And same in the other forum (https://forum.ansys.com/index.php?p=/discussion/29899/why-is-the-fdtd-solusion-of-the-microdisk-resonator-not-converged). If a legacy is not recommended, what boundary condition is suitable for this case?
January 25, 2022 at 8:02 amejlee0911SubscriberI apologize for the misunderstanding convergence test.
Simulated again and there is no difference between PML types. It shows identical results so I think it is okay to use a legacy uniaxial anisotropic PML. As I mentioned above, I wonder why do not recommend using that PML type?
January 28, 2022 at 1:51 amKyleAnsys EmployeeFrom the release notes from when that PML type was released:
The newstretched coordinate PML(SCPML) uses a state of the art formulation  that incorporates many recent advances and delivers a number of advantages including better absorption and greater numerical stability when compared to the uniaxial anisotropic PML (UPML) provided in earlier versions of the software.
The new SCPML tends to have better performance than the UPML, but If the results are identical when you switch between them then it shouldn't matter which one you use.
Viewing 4 reply threads
Ansys Innovation Space
- You must be logged in to reply to this topic.
Boost Ansys Fluent Simulations with AWS
Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.Trending discussions
- “Import optical generation” or “delta generation rate”?
- Why am I getting “process exited without calling finalize”, and how do I fix it?
- Error: addfdtd is not a valid function or a variable name
- Error on Lumerical device
- Using a license file on a new license server
- Ansys Insight: Transmission results greater than one
- Ansys Insight: Diverging Simulations
- Ansys Insight: About override mesh in FDTD: its use and settings
- Is there a Lumerical script command to output the Simulation and Memory requirements?
- Ansys Insight: Convergence issues in CHARGE
Top Rated Tags
© 2023 Copyright ANSYS, Inc. All rights reserved.Ansys does not support the usage of unauthorized Ansys software. Please visit www.ansys.com to obtain an official distribution.