# COMSOL Blog

## Application-Specific: Polar, Far-Field, and Particle Tracing Plots

##### Lexi Carver | February 2, 2015

In recent postprocessing blog posts, we’ve demonstrated different plot types that are typically used for common fluid, mechanical, chemical, and electrical applications. In the next several parts of this series, we’ll introduce a few more unusual plot types that are specific to unique applications and discuss some other tools that you can use to change the feel of your visualization. Here, we highlight polar, far-field, and particle tracing plots.

### Predicting Cavitation in Journal Bearings

##### Fabrice Schlegel | January 30, 2015

Journal bearings are lubricated components that support a rotating shaft. Cavitation affects the performance of these bearings and must be considered during the design stage. Here, I’ll explain what journal bearings are and why predicting cavitation is important, as well as share an industry example with you.

### How to Compute the Acoustic Radiation Force

##### Alon Grinenko | January 29, 2015

Acoustic radiation force is an important nonlinear acoustic phenomenon that manifests itself as a nonzero force exerted by acoustic fields on particles. Acoustic radiation is an acoustophoretic phenomenon, that is, the movement of objects by sound. One interesting example of this force in action is the acoustic particle levitation discussed in this previous blog post. Today, we shall examine the nature of this force and show how it can be computed using COMSOL Multiphysics.

### Using Perfectly Matched Layers and Scattering Boundary Conditions for Wave Electromagnetics Problems

##### Walter Frei | January 28, 2015

When solving wave electromagnetics problems, it is likely that you will want to model a domain with open boundaries — that is, a boundary of the computational domain through which an electromagnetic wave will pass without any reflection. COMSOL Multiphysics offers several solutions for this. Today, we will look at using scattering boundary conditions and perfectly matched layers for truncating domains and discuss their relative merits.

### Which Multiphase Flow Interface Should I Use?

##### Fabrice Schlegel | January 27, 2015

If you are interested in using COMSOL Multiphysics software to solve multiphase flow problems, you may be wondering which multiphase flow interface to choose. This is your guide to the six interface options available to you and when you should use them.

### How to Perform a 3D Analysis of a Semiconductor Device

##### Matt Pooley | January 26, 2015

Simulation of 3D semiconductors has the potential to be extremely useful when developing and improving semiconductor technology by reducing the amount of experimentation and fabrication required to design complex devices. Modeling 3D devices is challenging as the length scales that must be resolved, combined with the nonlinear nature of semiconductor physics phenomena, often require computationally expensive simulations. Here, we share an example simulation of a 3D bipolar transistor and important advice for effective modeling of 3D semiconductors with COMSOL Multiphysics.

### Dielectrophoretic Separation

##### Bjorn Sjodin | January 23, 2015

How can you use an electric field to control the movement of electrically neutral particles? This may sound impossible, but in this blog entry, we will see that the phenomenon of dielectrophoresis (DEP) can do the trick. We will learn how DEP can be applied to particle separation and demonstrate a very easy-to-use biomedical simulation app that is created with the Application Builder and run with COMSOL Server™.

### Cloaking Advancements for Flexural Waves in Elastic Plates

##### Fanny Littmarck | January 22, 2015

Previous work on cloaking for flexural waves in elastic plates presented limitations and near invisibility. Now, a research group in Europe has figured out a new theoretical framework to both overcome the limitations and achieve exact cloaking for flexural waves in Kirchhoff-Love plates. To visualize and test the quality of the cloak, they ran COMSOL Multiphysics simulations.

### Improving the Power of Optical Systems via Component Design

##### Nikola Strah | January 21, 2015

If you look up at the night sky, especially somewhere far away from city lights, you will see the stars twinkle. While an inspiration for poets and romantics throughout time, the beauty of the starry night sky has also been a challenge to astronomers studying the night sky and the universe. It has led to the development of adaptive optics, which is used nowadays to improve the power of optical systems beyond the obstacles imposed by the optical medium.

### Happy 240th Birthday, André-Marie Ampère

##### Bridget Cunningham | January 20, 2015

On this day, 240 years ago, the French physicist and mathematician André-Marie Ampère was born in Lyon, France. Recognized as a founder of electrodynamics — or what is today known as electromagnetism — Ampère helped establish a theory defining the relationship between electricity and magnetism. We continue to celebrate the importance of his discovery in creating the groundwork for future developments in both of these fields.

### From Books to Technology: Pop-Up Fabrication Techniques

##### Bridget Cunningham | January 19, 2015

The use of 3D structures in the design of pop-up books is a unique tool that fosters engagement in reading. Within the scientific community, researchers have found a use for these same fabrication techniques in the development of new technologies. We discuss these “pop-up” techniques and how they have shifted from libraries to research labs.