## Modeling Electrochemical Processes in a Solid-State Lithium-Ion Battery

##### Bridget Cunningham December 7, 2016

Traditional lithium-ion batteries use an electrolyte based on a flammable liquid solvent, which can cause them to catch fire if they overheat. In recent years, nonflammable solid electrolytes have been investigated as an alternative to improve battery design and safety. Optimizing this technology for industrial applications, however, requires a better understanding of the electrochemical processes inside the device. Simulation serves as a valuable tool for this purpose, helping to realize the use of solid-state lithium-ion batteries in the near future.

### Analyze a Variety of Rotating Machines with the Rotordynamics Module

##### Caty Fairclough December 6, 2016

When modeling a rotating machine, it’s important to study the vibrations influencing its behavior in order to avoid machine failure. One way to accomplish this is with the new Rotordynamics Module, an expansion to the add-on Structural Mechanics Module for the COMSOL Multiphysics® software. Today, we’ll introduce you to the Rotordynamics Module and walk you through its helpful features and functionality for improving your rotating machinery design process.

### Can a Stiffness Be Negative?

##### Henrik Sönnerlind December 5, 2016

In finite element modeling, you may encounter formulations where a force does not monotonically increase with displacement. You can see this property in many material models that include degradation of the material. Such behavior is represented by a negative stiffness. In this blog post, we discuss some examples of negative stiffness, including the physical backgrounds and numerical implications. These ideas are not confined to mechanical analysis, even though the term stiffness originates in that field.

### Why Is Ice Slippery Enough for Skiing and Skating?

##### Brianne Costa December 2, 2016

Finding a scientific explanation for why ice is slippery seems simple enough, but it has actually been a subject of debate and confusion for centuries. As part of the world begins to bundle up for a blustery winter, let’s explore the science behind how the slipperiness of ice enables us to ski, skate, and even fall down in the parking lot.

### Designing Effective Transdermal Drug Delivery Patches with Simulation

##### Bridget Paulus November 29, 2016

Transdermal drug delivery (TDD) patches continuously deliver drugs into the body for a certain amount of time. However, the skin is designed to keep out foreign substances, like drugs. To create a TDD patch that successfully bypasses this barrier, simulation can be used to study drug release and absorption into the skin. To analyze this process, Veryst Engineering created a TDD patch model with the COMSOL Multiphysics® software and compared the results to experimental data.

### How to Model Electrodynamic Magnetic Levitation Devices

##### Nirmal Paudel November 28, 2016

Electrodynamic magnetic levitation can occur when there are time-varying magnetic fields in the vicinity of a conductive material. In this blog post, we will demonstrate how to model this principle with two examples: a TEAM benchmark problem of an electrodynamic levitation device and an electrodynamic wheel.

### Using the Domain Decomposition Solver for Thermoviscous Acoustics

##### Jan-Philipp Weiss November 25, 2016

In a recent blog post, we discussed how to use the Domain Decomposition solver for computing large problems in the COMSOL Multiphysics® software and parallelizing computations on clusters. We show how to save memory by a spatial decomposition of the degrees of freedom on clusters and single-node computers with the Recompute and clear option. To further illustrate the Domain Decomposition solver and highlight reduced memory usage, let’s look at a thermoviscous acoustics problem: simulating the transfer impedance of a perforate.

### How to Analyze Your SOLIDWORKS® Designs with an App

##### Lorant Olasz November 24, 2016

For many years, it’s been possible to analyze synchronized CAD geometries in COMSOL Multiphysics® via the LiveLink™ interfacing products. But did you know that you can also incorporate this functionality into an easy-to-use simulation app? With an app, you can dynamically modify your geometry in a CAD program such as SOLIDWORKS® and use this information to analyze new product designs. Today, we will demonstrate how to do so, using the new Bike Frame Analyzer app as an example.

### Using the Domain Decomposition Solver in COMSOL Multiphysics®

##### Jan-Philipp Weiss November 23, 2016

The Domain Decomposition solver is a memory-efficient iterative algorithm with inherent parallelism on the geometric level. We can use this method to compute large modeling problems that can’t be solved with other direct or iterative methods. This solver’s primary field of application is on clusters, but it can also enable the solution of large problems on laptops and workstations. Let’s see how to use this functionality in the COMSOL Multiphysics® software.

### Designing a Power Generation Source for Bicycle Safety Lights

##### GuestRune Thygesen November 22, 2016

Today, we invite guest blogger Rune Thygesen of Reelight to discuss designing a power generation source for bicycle safety lights using simulation. At Reelight, we are developing an affordable bicycle safety light that is extremely easy for the end user to install. Along with a stronger and more flexible mounting system, we needed to develop a new power generation platform. Using simulation-based design, we created a power platform that is easy to use and quick to install.

### Why Doesn’t the Ice Cream in a Baked Alaska Melt?

##### Magnus Ringh November 18, 2016

One dessert that is sure to amaze your dinner guests is the baked Alaska. This classic treat consists of ice cream placed on a bed of sponge cake and covered in meringue. Although the dessert goes into a hot oven to caramelize the meringue, the ice cream inside surprisingly remains frozen. In this blog post, we use the heat transfer simulation capabilities of the COMSOL Multiphysics® software to find out how the baked Alaska works.