## How to Implement the Fourier Transformation from Computed Solutions

##### Yosuke Mizuyama February 27, 2017

We previously learned how to calculate the Fourier transform of a rectangular aperture in a Fraunhofer diffraction model in the COMSOL Multiphysics® software. In that example, the aperture was given as an analytical function. The procedure is a bit different if the source data for the Fourier transformation is a computed solution. In this blog post, we will learn how to implement the Fourier transformation for computed solutions with an electromagnetic simulation of a Fresnel lens.

### Analyzing Novel Roof Tile Designs with Multiphysics Simulation

##### Caty Fairclough February 23, 2017

Maintaining cool temperatures in buildings is necessary to keep people comfortable, particularly for those living in hot climates. For houses that aren’t optimized for thermal performance, cooling requires large amounts of energy and money. To reduce these costs, researchers from the University of Ferrara, Italy looked to improve roofs as part of the Life HEROTILE project. To accomplish this, they modeled novel roof tiles that are designed to increase air permeability and lower cooling costs.

### Solving Shallow Water Equations with Equation-Based Modeling

##### Caty Fairclough February 21, 2017

The COMSOL Multiphysics® software includes many built-in physics equations and interfaces, but there may be times when you need to implement physics that aren’t part of the software to solve your modeling problem. You can use the flexibility of the COMSOL® software to add user-defined equations via equation-based modeling. Today, we discuss using equation-based modeling to solve a shallow water equation, which can be used to analyze coastal erosion.

### Improving the Design of Monolithically Integrated Magneto-Optic Routers

##### Caty Fairclough February 17, 2017

While electro-optic (EO) routers are currently used in on-chip optical communication systems, they may require too much power for some applications. In these situations, we can look to monolithically integrated magneto-optic (MO) routers as low-power alternatives. Designing these routers can be challenging. With multiphysics simulation, we can analyze on-chip MO routers and the manufacturing techniques used to create them.

### Happy Birthday, Galileo Galilei

##### Caty Fairclough February 15, 2017

Galileo Galilei is known for his research in many fields, such as physics and astronomy. He researched theories of relativity and motion and remained devoted to his studies, even in the face of opposition. As today is the anniversary of his birthday, we’d like to take a brief look at a few of Galileo Galilei’s major accomplishments.

### How to Model the Electromagnetic Heating of Underground Cables

##### Walter Frei February 14, 2017

Overhead power cables can be seen almost everywhere in the United States, but there are also many underground power cables that we can’t see. They have the advantage of protection from wind and snow damage and, due to their shielding, have greatly reduced electromagnetic field emission. One disadvantage of underground cables is that they heat up significantly, which leads to degradation of the insulation and failure. Let’s see how to model electromagnetic heating in the COMSOL Multiphysics® software.

### Which Porous Media and Subsurface Flow Interface Should I Use?

##### Peter Lyu February 13, 2017

Simulating fluid flow underground or in other porous media is common in a number of engineering fields, such as agricultural, chemical, civil, and nuclear engineering. To help engineers and scientists simulate different types of porous media flow, the COMSOL Multiphysics® software provides a comprehensive set of physics interfaces. Today, we will go over the various interfaces that you can use and discuss how to choose the best one for your application.

### Electrochemical Impedance Spectroscopy: Experiment, Model, and App

##### Edmund Dickinson February 9, 2017

Electrochemical impedance spectroscopy is a versatile experimental technique that provides information about an electrochemical cell’s different physical and chemical phenomena. By modeling the physical processes involved, we can constructively interpret the experiment’s results and assess the magnitudes of the physical quantities controlling the cell. We can then turn this model into an app, making electrochemical modeling accessible to more researchers and engineers. Here, we will look at three different ways of analyzing EIS: experiment, model, and simulation app.

### Efficiently Verify Electric Fields Outside Electrical Installations with Apps

##### Bridget Cunningham February 8, 2017

Electrical installations must often adhere to requirements for the maximum electric field levels in their surrounding area. Electric fields that are too high can be harmful to both operators and the general public. Simulation is typically used to verify that these levels meet the requirements, otherwise significant redesigns may be needed much later on. The Application Builder enables design engineers to perform verification studies earlier in the process.

### How and When to Open Recovery Files in COMSOL Multiphysics®

##### Andrew Griesmer February 7, 2017

The Open Recovery File feature is a somewhat unknown feature in the COMSOL Multiphysics® software, but it’s useful for anyone running simulations that give multiple solutions. If, for any reason, the software shuts down before the simulation finishes, you can open a recovery file so that you don’t lose your work. Here, we highlight a tutorial video on how to open these files to recover “lost” work as well as go over the strengths and limitations of this feature.

### Preventing Bubble Entrapment in Microfluidic Devices Using Simulation

##### Bridget Paulus February 6, 2017

If bubbles in a microfluidic device become stuck, it can cause the device to malfunction. Bubble entrapment depends on several factors, including the geometry and flow characteristics of the microchannel, as well as the surface properties of its walls. To study these aspects, Veryst Engineering modeled a bubble in a microchannel using the COMSOL Multiphysics® software. Today, we look at their results, which shed light on the device geometries and contact angles that lead to bubble entrapment.