Latest Posts
Using Adaptive Meshing for Local Solution Improvement
One of the perennial questions in finite element modeling is how to choose a mesh. We want a fine enough mesh to give accurate answers, but not too fine, as that would lead to an impractical solution time. As we’ve discussed previously, adaptive mesh refinement lets the software improve the mesh, and by default it will minimize the overall error in the model. However, we often are only interested in accurate results over some subset of the entire model space. […]
Learning to Solve Multiphysics Problems Effectively
One of the questions we get asked often is how to learn to solve multiphysics problems effectively. Over the last several weeks, I’ve been writing a series of blog posts addressing the core functionality of the COMSOL Multiphysics software. These posts are designed to give you an understanding of the key concepts behind developing accurate multiphysics models efficiently. Today, I’ll review the series as a whole.
Optimizing Recloser Performance with Simulation
During snow storms or windy days, a branch might break and short-circuit a power line’s electric current as it falls. The first task of a recloser is to interrupt this short-circuit, i.e. to open or disconnect the affected overhead line from the feeding network source. The second task is to try to re-establish power after a short time by to re-closing the line, taking advantage of the fact that most of the reasons for a short-circuit of an overhead line […]
Improving Convergence of Multiphysics Problems
In our previous blog entry, we introduced the Fully Coupled and the Segregated algorithms used for solving steady-state multiphysics problems in COMSOL. Here, we will examine techniques for accelerating the convergence of these two methods.
Modeling Bone Strength Using Isotropic and Anisotropic Materials
The question of exactly how strong living bones are poses many important considerations for the medical industry. There is not currently a single-purpose device in the field to test bone strength. However, it is possible for researchers to get measurements of bone strength by modeling the entire makeup of the bone and using multiphysics simulation to perform stress and strain analyses. Simulating bone strength starts with a simple map of the external topology of the bone and then delves into […]
Optimizing Dialyzer Design Using Multiphysics Simulation
A while back, I had the opportunity to speak with Steven Conrad, a critical care physician at the Louisiana State University (LSU) Health Science Center in New Orleans. Not only is Dr. Conrad a physician as well as a professor at LSU, he’s also a biomedical engineer who uses finite element analysis (FEA) to conduct research on the design of dialyzers. Dr. Conrad uses COMSOL Multiphysics to gain a deeper understanding of the physics behind these devices, and to create […]
Simulating Viscous Fingering Using Equation-Based Modeling
A prospective user of COMSOL approached me about modeling viscous fingering, which is an effect seen in porous media flow. He hadn’t found a satisfying solution elsewhere, so he turned to COMSOL. I’d like to share with you some of my insight on how to go from idea to model to simulation by taking a “do-it-yourself approach” and utilizing the equation-based modeling capabilities of COMSOL Multiphysics.
Predicting Microwave Drying of Potatoes
You may not think of reheating food in the microwave as a drying process, but as we saw at the COMSOL Conference 2013 Boston, microwave technology — the same technology used in domestic microwave ovens — can be used for drying fruits and vegetables. One poster presented at the conference featured microwave drying of potatoes and how the heat and mass transfer that occurs can be modeled to predict the drying process.
Solving Multiphysics Problems
Here we introduce the two classes of algorithms used to solve multiphysics finite element problems in COMSOL Multiphysics. So far, we’ve learned how to mesh and solve linear and nonlinear single-physics finite element problems, but have not yet considered what happens when there are multiple different interdependent physics being solved within the same domain.
2D Materials, It’s Not Just About Graphene
You’ve heard the story: a couple of scientists discovered graphene when they repeatedly pulled a strip of adhesive tape off a layer of graphite. Graphene has been all the rage due to its incredible strength, low weight, and electronic properties, but it’s not the only material of its kind. There are plenty of other 2D materials to consider for electrical applications — some of which may work together with graphene, and others that can be used in its place.
Thermal Modeling of Surfaces with Wavelength-Dependent Emissivity
Whenever we are solving a thermal problem where radiation is significant, we need to know the emissivities of all of our surfaces. Emissivity is a measure of the ability of a surface to emit energy by radiation, and it can depend strongly upon the wavelength of the radiation. This is very relevant for thermal problems where the temperature variation is large or when there is exposure to a high-temperature source of radiation such as the sun. In this post on […]
Microwave Plasmas
Microwave plasmas, or wave-heated discharges, find applications in many industrial areas such as semiconductor processing, surface treatment, and the abatement of hazardous gases. This blog post describes the theoretical basis of the Microwave Plasma interface available in the Plasma Module.
Meshing Considerations for Nonlinear Static Finite Element Problems
As part of our solver blog series we have discussed solving nonlinear static finite element problems, load ramping for improving convergence of nonlinear problems, and nonlinearity ramping for improving convergence of nonlinear problems. We have also introduced meshing considerations for linear static problems, as well as how to identify singularities and what to do about them when meshing. Building on these topics, we will now address how to prepare your mesh for efficiently solving nonlinear finite element problems.
Photos from the COMSOL 4.4 Launch Event in Silicon Valley
In anticipation of the COMSOL 4.4 release, the COMSOL office in Palo Alto decided to try something new. Feeling inspired by the very successful COMSOL Conference in Boston, we held an all-day launch event in Silicon Valley. Here’s a round-up of the event and some of the photos we took.
New Mixer Module Showcases CFD Capabilities of COMSOL
The Mixer Module provides ready-made interfaces for describing the difficult problem of laminar and turbulent flows in rotating machinery with free liquid surfaces. COMSOL has been developing different techniques for modeling CFD, moving geometries, and free surfaces during the past few years for a number of different applications. This has now culminated in the new Mixer Module that was released with version 4.4, and it clearly showcases the improved CFD capabilities of COMSOL.
COMSOL 4.4 Brings Particle-Field and Fluid-Particle Interactions
The trajectories of particles through fields can often be modeled using a one-way coupling between physics interfaces. In other words, we can first compute the fields, such as an electric field, magnetic field, or fluid velocity field, and then use these fields to exert forces on the particles using the Particle Tracing Module. If the number density of the particles is very large, however, the particles begin to noticeably perturb the fields around them, and a two-way coupling is needed […]
3D Printing: Material Matters
In the past, we’ve discussed a few of the extraordinary uses of 3D printing (or additive manufacturing) technology by some innovative engineers, and even printed a few of our COMSOL models. In one of our previous posts on 3D printing, we discussed some of the limitations that this technique poses from both a consumer and manufacturing stand-point — you can only print one material at a time. Now however, as was mentioned in an article in Desktop Engineering, not only […]
Nonlinearity Ramping for Improving Convergence of Nonlinear Problems
As we saw in “Load Ramping of Nonlinear Problems“, we can use the continuation method to ramp the loads on a problem up from an unloaded case where we know the solution. This algorithm was also useful for understanding what happens near a failure load. However, load ramping will not work in all cases, or may be inefficient. In this posting, we introduce the idea of ramping the nonlinearities in the problem to improve convergence.
COMSOL 4.4: Magnetic Saturation Curves at your Fingertips
When designing inductive devices, both challenges and possibilities are associated with the nonlinear behavior of ferromagnetic materials. COMSOL Multiphysics is well-adapted to the solution of highly nonlinear numerical models but high-fidelity modeling of nonlinear inductive devices also requires accurate material data. To meet this challenge, a library of 165 nonlinear magnetic materials is provided in COMSOL 4.4, bringing new powers to the design and modeling of electric motors, transformers, relays, etc. Here, we will discuss how the modeling process is […]
Dedicated Multiphysics Node Introduced in COMSOL 4.4
To make it easier and more transparent to define models involving multiple physics phenomena in COMSOL, a separate Multiphysics node has been added as a new feature in COMSOL version 4.4. The Multiphysics node gives you control over the couplings for thermal stress and electromagnetic thermal effects involved in your models. Future versions will include further multiphysics couplings through the Multiphysics node in addition to the multiphysics couplings methods already available since previous versions.
Video Tutorial: Introducing the New User Interface in COMSOL 4.4
Each COMSOL release aims to create a better modeling experience for our users, usually in the form of new add-on modules and new functionality in existing products. COMSOL 4.4 brings you all that, but it also includes another significant change: a brand new user interface (UI). The new UI contains a ribbon at the top of the interface (for our Windows® users) to make your modeling easier and faster. The ribbon gives you direct access to the functions you would […]
COMSOL Multiphysics Version 4.4 Released Today
You’ve seen glimpses of our new software release at the COMSOL Conference and perhaps engaged in commentary around it in social media. Today marks the official release of COMSOL Multiphysics version 4.4, and you can now learn about the software updates in detail and download it if you are on subscription.
Your Room, from Interior Design to Acoustics
I recently stumbled upon a neat tool from Autodesk® called “Autodesk® Homestyler”. It’s surprising to see they have rolled out a tool that is more entertaining than utilitarian, but if a CAD company were to develop something fun for the general population, I suppose an interior design app makes sense. We took it for a test-drive. Here’s how it went.
The Next Generation of Moore’s Law
At the COMSOL Conference in Boston, Lam Research Corporation held a keynote talk about Moore’s law and its role in computational modeling. The keynote touched on how Moore’s law has not only impacted the advancement of simulation tools, but also how the development of these tools have themselves allowed Moore’s law to hold true. The concept was something that interested me, and I know it’s been on the minds of many electrical engineers as well. Case in point, when browsing […]