## Improving Convergence of Multiphysics Problems

##### Walter Frei | December 23, 2013

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.

Read More##### Laura Bowen | December 20, 2013

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 […]

Read More##### Alexandra Foley | December 19, 2013

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 […]

Read More##### David Kan | December 18, 2013

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.

Read More##### Lexi Carver | December 17, 2013

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.

Read More##### 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.

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