# COMSOL Blog

## Do Hybrid and Electric Vehicles Have the Pulling Power?

##### Edmund Dickinson | April 22, 2015

You might think you’re a smooth driver — but your engine probably doesn’t. Everyday obstructions like traffic lights and changing speed limits mean that the power demands of a car drivetrain vary rapidly. Since we expect new technologies like hybrid or electric vehicles to match the performance of existing cars in responding instantly to the demands of our right foot, designers need to make sure that this is possible and safe. One part of this involves modeling batteries.

### Phase Decomposition Analysis of Loudspeaker Vibrations

##### René Christensen | April 21, 2015

Today we welcome guest blogger René Christensen from Dynaudio A/S. When evaluating loudspeaker performance, dips and/or peaks in the on-axis sound pressure level can be a result of an unfortunate distribution of phase components. To overcome this, we use a phase decomposition technique that splits a total surface vibration into three components depending on how they contribute to the sound pressure in an arbitrary observation point; either adding to, subtracting from, or not contributing to the pressure.

### Evaluating a UHF RFID Tag Design with Simulation

##### Fanny Littmarck | April 20, 2015

COMSOL Multiphysics version 5.1 introduces a new tutorial model of a UHF RFID tag. RFID tags allow you to identify and monitor both inanimate objects and living creatures through the use of electromagnetic fields. The UHF RFID tag has a wider range than other types of RFID tags and is often used to identify animals. We can evaluate the performance of the tag through an analysis of the electric field and far-field radiation pattern.

### Implementing the Weak Form with a COMSOL® App

##### Chien Liu | April 16, 2015

Previously in our weak form series, we discretized the weak form equation to obtain a matrix equation to solve for the unknown coefficients in our simple example problem. Following the same procedure as in this previous blog post, we will implement the equation in the COMSOL Multiphysics® software with additional steps included to examine the matrices. We will find it more convenient to use a COMSOL® software application to display all relevant matrices at once, arranged logically on one screen.

### What to Expect from COMSOL Multiphysics Version 5.1

##### Fanny Littmarck | April 15, 2015

Today marks the release of COMSOL Multiphysics version 5.1. The latest COMSOL software version brings you 20 demo apps and many new features and functionality updates to numerous products. Here’s what you can expect after downloading version 5.1.

### Which Module Should I Choose for Working with My CAD Data?

##### Walter Frei | April 14, 2015

There are several different add-on modules to the COMSOL Multiphysics® software for working with external CAD and ECAD data. These modules allow both unidirectional and bidirectional data transfer between the COMSOL Multiphysics analysis tools and the CAD and ECAD software that you are using for design. In this blog post, we will cover the functionality of these various modules and describe why you may want to use them.

### Modeling Laser-Material Interactions with the Beer-Lambert Law

##### Walter Frei | April 13, 2015

High-intensity lasers incident upon a material that is partially transparent will deposit power into the material itself. If the absorption of the incident light can be described by the Beer-Lambert law, it is possible to model this power deposition using the core functionality of COMSOL Multiphysics. We will demonstrate how to model the absorption of the laser light and the resultant heating for a material with temperature-dependent absorptivity.

### How Can I Build an Efficient Stirling Heat Pump?

##### Phillip Oberdorfer | April 9, 2015

Stirling engines, or heat pumps, are systems that are able to work on incredibly low temperature differences. In fact, some types of Stirling engines only need human body heat in order to operate. Here, we explore the dynamics of this interesting machine that you can build at home and demonstrate how to model it using COMSOL Multiphysics.

### The Boltzmann Equation, Two-Term Approximation Interface

##### Annette Meiners | April 8, 2015

In a previous blog post, we introduced readers to different kinds of electron energy distribution functions (EEDFs) and their importance in plasma modeling. Today, we focus our attention on the Boltzmann Equation, Two-Term Approximation interface, demonstrating its use with an example from our Model Library.

### Using the Boussinesq Approximation for Natural Convection

##### Fabrice Schlegel | April 7, 2015

Today, we compare the Boussinesq approximation to the full Navier-Stokes equations for a natural convection problem. We also show you how to implement the Boussinesq approximation in COMSOL Multiphysics software and discuss potential benefits of doing so.

### Using Lead Rubber Bearings in Base Isolation Systems

##### Bridget Cunningham | April 6, 2015

When an earthquake strikes, the force from its seismic waves can weaken the stability of buildings. By implementing seismic control measures, designers can enhance the flexibility of such structures as well as strengthen their safety levels. See how one research team used COMSOL Multiphysics to study the impact of base isolation systems and explore approaches to optimizing their performance.