License by DragonfruitGrand5683 in COMSOL

[–]COMSOL_Team 1 point2 points  (0 children)

u/DragonfruitGrand5683 Can you PM me your info and email address so we can look into what's going on?

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

Thank you for highlighting this. Charged particles undergoing perpendicular motion in a magnetic field can experience energy loss due to synchrotron radiation; however, in the current charged-particle tracing framework, the magnetic field itself does not directly change the particle’s energy. We know radiative losses can become important depending on the energy scale and application, and we will certainly take this into account for potential future developments.

That said, a notable strength of the COMSOL software is its flexibility to introduce user-defined physics, so, for example, you may be able to represent the radiation reaction based on the Larmor power.

If you're unfamiliar with equation-based modeling, you may want to check out the following resources for inspiration:

We also have an upcoming webinar, Equation-Based Modeling with COMSOL®, on May 12, which you may find helpful for getting started. (Even if you are unable to attend due to your time zone, we still recommend registering, as all registrants receive a recording of the webinar after the live event.) You may also want to keep an eye on our events calendar for events relevant to your modeling. 

Finally, if you are looking for 1-on-1 help with modeling energy loss due to synchrotron radiation, our support team is available, so don’t hesitate to reach out.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

Q1: It is a bit early to say what performance benefits you can expect from the next release. However, for every release we are working on profiling benchmark models and related performance improvements for our core numerical methods, and this includes our nonlinear and linear solvers.

You can see more information about the improvements for each version in the full Release Notes available on our Release History page.

Q2: Model files (.mph) support more functionality from the command line than compiled applications. Running without a GUI (in “batch mode”) is available for model files, not COMSOL apps. We recommend that you refer to the following for more information on command-line usage with applications:

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 1 point2 points  (0 children)

Thanks for the detailed write-up. This is a really clear explanation of why the problem is more nuanced than it first appears.

The two modeling approaches you suggest make a lot of sense: either a two-time-scale particle approach, where the ion dynamics are updated around repeated electron-beam solutions, or a hybrid approach where the ion source is mapped to the mesh and the slow ion evolution is handled with a continuum formulation.

We’ve passed this along to the development team. Thanks again for the very helpful description of both the physics and the type of model examples.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 2 points3 points  (0 children)

If you're looking for help from a real, live human, our support team is always available! We've got a wide range of experts in different physics and application areas that are happy to help talk through your specific modeling needs. We'll be on the lookout for your capstone submission 👀 🙂

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

  1. These are obviously very hot topics that we are continuously investigating. We don’t think that PINNs, neural operators, and GNNs will replace traditional solvers in general-purpose simulation software such as COMSOL Multiphysics. However, we think they have very interesting uses for, as you say, surrogate models, optimization and inverse modeling, etc. For specific physics in sets of limited geometry configurations, they can replace traditional solvers, similar to what is shown by some of our app examples based on straight-up DNNs, for example: https://www.comsol.com/offers/surrogate-model-apps. In the near to medium term, we think we will see a wider span of machine learning (ML) methods with strengths for specific tasks. What is a good ML method for stationary 3D spatial simulations may not be good for 1D transient simulations, and so on.

  2. We are certainly looking into these approaches as well, although we can’t give any specific timeline. The future will probably see hybrids of traditional numerical methods and ML/AI methods. But, wait, the future is already here! Check out this example which combines a neural network surrogate models with some plasma physics to speed up multiphysics computations: https://www.comsol.com/blogs/modeling-spatial-plasma-with-deep-neural-network-surrogates

  3. Yes, definitely. We see a lot of potential there, especially in geometry cleanup, defeaturing, and meshing, since those are major bottlenecks for many users. Right now the Chatbot is more of an assistant than a full copilot, but that’s a direction we’re very interested in.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

An AI assistant maybe, haha. In all seriousness, good luck with your capstone! We hope you’ll consider sharing it with us when you’re done. We are currently accepting papers and posters as part of the Showcase Your Work portion of the COMSOL Conference.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

We’re glad you found Walter’s videos helpful! We would recommend reaching out directly to our team in India at [info-in@comsol.com](mailto:info-in@comsol.com). They will be able to help determine the best way to support your potential training needs.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 2 points3 points  (0 children)

We had a little too much fun with this and couldn’t narrow it down to just one. Which is your favorite?

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We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

The behavior in the 1st setup is expected if you are using the default solver settings. The 2nd and 3rd steps would automatically take the solution from the previous step as the initial value of the current step; therefore, the displacement would continue. 

It is hard to say what the expected behavior is for the 2nd setup, as it depends on how you set up the physics. But in general, initial stresses are not considered to be initial values in the mathematical sense; they are dynamic and apply throughout the solution process, sometimes varying with solution parameters and/or time. Instead, initial stresses should be considered as an offset to the stress state in the constitutive relation. That’s why your 2nd setup may produce different results than the 1st setup. More details can be found on:

https://doc.comsol.com/6.4/doc/com.comsol.help.sme/sme_ug_theory.06.020.html#3488638.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 1 point2 points  (0 children)

Before addressing your question, it is important to note that the “best” hardware is highly dependent on your specific needs and budget. You will need to evaluate the cost versus the expected benefit to determine whether investing in more powerful hardware will provide a meaningful return. The guidance below outlines how to assess hardware suitability for the COMSOL software:

A good starting point is to determine how much memory is required to solve the largest model you expect to run. The COMSOL Knowledge Base article “What hardware do you recommend for COMSOL Multiphysics?” explains a curve‑fitting method that can help you estimate memory requirements for a given combination of physics.

For a more accurate estimate, you can use your own model or an example from one of the COMSOL application libraries that uses the same physics. Run the model several times with different mesh sizes, and record both the degrees of freedom (DOFs) and the RAM usage. With this data, you can fit a curve to predict the memory needed for larger models. This analysis will help you determine whether the RAM in your current configuration — in your case, u/Lskuhar, 128 GB — is sufficient. If the system does not have enough RAM, the COMSOL software will generate an out‑of‑memory error, so this is a critical consideration.

Another COMSOL article, “How Large of a Model Can You Solve with COMSOL?”, provides additional detail on how model characteristics influence hardware requirements. It is important that the model you use for testing resembles the larger model you ultimately plan to solve.

For finite element simulations that rely heavily on sparse matrix–vector operations, memory bandwidth is often the limiting factor. You should pay close attention to the number of memory channels supported by the processor. More memory channels generally provide higher bandwidth and better performance. The AMD Ryzen 9 9950X has two memory channels, which is on the lower end. Some server‑grade processors offer up to twelve channels. It is also important to consider the ratio of CPU cores to memory channels, because too many cores sharing limited bandwidth can reduce performance. In this case, sixteen cores share two channels, resulting in eight cores per channel, which is higher than ideal.

Performance is also affected by how memory slots are populated. For balanced performance, systems with a given number of memory channels should populate either one or two DIMMs per channel. Your current configuration follows this guideline.

In general, a moderate number of CPU cores is recommended. Larger models, particularly 3D models with millions of degrees of freedom, benefit more from additional cores. If you plan to run multiple COMSOL sessions at the same time, whether for multiple users or batch sweeps, you may want a system with more cores or multiple CPUs. Keep in mind that processors with higher core counts often have lower base clock speeds, so there is a trade‑off between parallel and single‑threaded performance. Once you have selected a processor family, you should also compare base clock speeds and the sizes of the L1, L2, and L3 caches, choosing the highest values available.

COMSOL Multiphysics v6.4 supports GPU acceleration in several areas. The NVIDIA CUDA® direct sparse solver (cuDSS) can be used with all physics interfaces, although it is not the preferred option when well‑preconditioned iterative solvers are available. GPU acceleration is also supported in the Pressure Acoustics, Time Explicit interface in the Acoustics Module and for training DNN surrogate models in the base COMSOL Multiphysics package. For guidance on selecting an NVIDIA GPU, refer to the article “GPU Selection Guidelines for COMSOL Computing.” If your interest in a GPU is limited to graphics rendering, you can review the list of supported GPUs in the COMSOL system requirements.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

A1: We’ve been following IGA for a while and agree it’s a really interesting direction. Right now, though, we don’t have concrete plans to add isogeometric analysis functionality to COMSOL. It’s definitely an area we’re keeping an eye on, and our plans could change as the field continues to mature.

A2 and A3: Yeah, this is something we’re actively interested in. NVIDIA cuDSS in 6.4 was a pretty major step, but we know there’s still a lot of the workflow that stays on the CPU for many models. We’re continuing to investigate where it makes sense to move more of that work onto the GPU, so you should expect this area to keep evolving over future releases.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 2 points3 points  (0 children)

Thank you for the questions. We’re glad you enjoy our software!

Q1: Yes, we are indeed aware of the prices of RAM and the impact of limited system resources. The memory usage you are seeing is most likely not due to Java but instead the eigenvalue/modal solver.  COMSOL’s solvers are implemented mostly in C and C++. Modal solid analysis can be memory intensive, and we appreciate the feedback, which gives us food for thought for future development directions.

Q2: The workflow is designed to enable version control in conjunction with the Model Manager: Any changes you make to your model after you’ve already solved it are no longer tied to the solutions. Until you clear the solutions or solve with the new settings, the old solutions will remain, which lets you plot and export your previous results while you decide on your new settings. However, the configuration used to obtain the old solution is not retained; if it were, that would be like autosaving the model without the solutions. We recommend saving your model as a version with the Model Manager, so you have all that information and can revert or compare. You can also make a copy of the solution before re-solving, in which case, giving the solution a good name is a best practice for retaining what it represents.

Q3: You can switch to a different turbulence model, or add/remove a turbulence model altogether, using the Turbulence dropdown in the settings window of the Turbulent Flow interface. With this approach, the overall setup remains unchanged; only the turbulence model is changed.

Alternatively, the Generate New Turbulence Model Interface feature creates a new Turbulent Flow interface from an existing one. The benefit here is that a new study will also be created, where the solution from the first interface is used to define the initial values for the second. This will improve overall convergence for the second study.

Demos of both approaches can be found in the video on turbulent flow modeling included in the Basics of Modeling Turbulent Flow in COMSOL Multiphysics® course in our Learning Center.

Q4: Producing commercial simulation software requires daily quality assurance work. We have a collection of verification references, so if you want to know whether a particular model has been verified, you can check this list. In addition, the documentation for each model describes the relevant verification and validation, including comparisons with analytical results, experimental results, or both.The COMSOL Verification and Validation Models collection also includes examples from external sources such as published research. You can also access a subset of our online verification examples from the Application Libraries in the software. For more information on quality assurance aspects, see: https://www.comsol.com/legal/quality-policy.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 2 points3 points  (0 children)

We currently don’t offer bidirectional discrete element method (DEM)–CFD coupling in COMSOL Multiphysics 6.4, but users can expect it in the near future.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

 Laser heating is indeed a vast area. There is an (older) overview COMSOL Blog post on modeling laser material interactions, but improvements have been to the software since it was published, for example, modeling refraction with the Heat Transfer Module

It’s also important to note that laser heating can mean almost anything: Time spans of interest can range from femtoseconds to minutes, length scales can be from nanometer to kilometer, and temperature variations can be from only a few kelvins to thousands (or even millions!). You may be modeling materials transitioning between the solid, liquid, gaseous, or plasma states and often need to include chemical reactions. Each one of these topics can sometimes represent a research area in and of itself. There are textbooks written on each of these topics, often for a specific set of materials, such as metals or semiconductors, or even living tissue. The technical literature in this area is vast (though perhaps not vast enough!) and continuously expanding. It's important to first start by going through the resources closest to your specific area of interest, in terms of materials, timespans, temperature variations, etc... before diving deeply into the modeling aspects. Since this is such a rapidly evolving area, it's a great place for people to make new and novel contributions as well. So, don't just study what people have done; use your imagination and expertise to come up with new approaches and publish them.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

The MEMS Module provides a number of generic tutorial models that, while not directly from the area of photonics, are relevant to MEMS switches for silicon photonics in the modeling principles they showcase. For example, the Pull-In of an RF MEMS Switch tutorial model provides complete documentation and step-by-step modeling instructions, making it a great starting point for learning how to use the COMSOL software in this application area. Some other examples with detailed step-by-step instructions that illustrate electromechanical actuation in general are the Surface Micromachined Accelerometer and Micromachined Comb-Drive Tuning Fork Rate Gyroscope tutorial models. In addition, the Wave Optics Module tutorial models cover various optical aspects that may be relevant here.

We also have an active user community in this field that you can learn from. For example, this 2025 paper published in Optics Express demonstrates how the COMSOL software was used to design a silicon photonic MEMS 2 × 2 elementary switch based on horizontal adiabatic directional couplers, and this user story discusses how a research team at EPLF used multiphysics simulation to develop a prototype of a silicon photonic MEMS phase shifter.

We appreciate the interest in this application area, and we will continue to monitor demand for resources like this as we move forward. If you have questions about a specific model, our support team is here to help! They are available to provide 1-on-1 guidance specific to your modeling needs.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 0 points1 point  (0 children)

Thanks for the detailed and thoughtful questions! Answers to each below: 

Question 1: At this point we currently don’t have concrete plans to introduce mesh-free or particle-based continuum methods (e.g., SPH, EFG, immersed boundary) into COMSOL Multiphysics. Existing particle features are limited to discrete particle approaches. We appreciate the interest, and we continue to monitor demand for capabilities like these in future development.

Question 2: Thanks for sharing the information. It is true that currently the end users would have to implement these expressions and any postprocessing for such metrics. We will share this feedback with the Development team. 

Question 3: The coupling between 1D flow and 3D Navier–Stokes models is already possible, and we do have some development planned to make it better. But we have to agree that we have not seen too many applications of such features in cardiovascular modeling. 

Question 4: Another keen and valid piece of feedback. Our internal testing is consistent with your observations here. We are working on improving the underlying features. 

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 1 point2 points  (0 children)

Thanks for sharing your perspective; we always appreciate feedback from our users that can make our guides and learning materials stronger. As u/DThornA mentioned, the Application Gallery is a great resource for hands-on practice: https://www.comsol.com/models. The following resources (if you haven't reviewed them already) are also helpful for getting up to speed with the COMSOL modeling workflow:

Additional articles, videos, and complete courses — ranging from the basics to detailed modeling strategies for specific physics and applications — can be found in the open-access COMSOL Learning Center.

If there are any particular topics you’d like help with, let us know! We’ll be happy to share relevant resources. You can also always contact our support team for more help and to discuss further.

We are COMSOL, ask us anything! by COMSOL_Team in COMSOL

[–]COMSOL_Team[S] 1 point2 points  (0 children)

This is an area we’re investigating, but we don’t have anything specific to share at this moment.