## Solving Multiphysics Problems

##### Walter Frei | December 16, 2013

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.

Read More##### Fanny Littmarck | December 13, 2013

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.

Read More##### Walter Frei | December 12, 2013

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 […]

Read More##### Daniel Smith | December 11, 2013

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.

Read More##### Walter Frei | December 10, 2013

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.

Read More##### Ayana Simmons | December 9, 2013

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.

Read More##### Phil Kinnane | December 6, 2013

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.

Read More##### Christopher Boucher | December 5, 2013

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 […]

Read More##### Alexandra Foley | December 4, 2013

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 […]

Read More##### Walter Frei | December 3, 2013

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.

Read More##### Magnus Olsson | December 2, 2013

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 […]

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