# COMSOL Blog

## What Is the Doppler Effect?

##### Alexandra Foley | July 15, 2013

The Doppler effect, or Doppler shift, is the change in wavelength and frequency caused by the movement of an observer relative to the source. One of the most common ways we can experience the Doppler effect in action is in the change of pitch that occurs due to a moving sound source. You’ve probably experienced the Doppler effect when a fire truck or ambulance passes by with its sirens blaring. As the siren passes, the pitch suddenly drops as the […]

### Can You Use Heat Transfer to Predict Migration of Contaminants?

##### Alexandra Foley | July 10, 2013

The flow of fluid through a porous medium is usually described by Darcy’s Law. However, what if you wanted to look at a combination of fluid flow, heat transfer, and mass transport in a porous medium? Instead of using Darcy’s Law, which calculates an average linear velocity for fluid flow in porous media, the Navier-Stokes equations would be necessary in order to obtain accurate results. In addition, heat convection and conduction, as well as mass transport would need to be […]

### Simulating an Engine Governor, the Spring Loaded Centrifugal Governor

##### Alexandra Foley | July 5, 2013

We’ve probably all seen centrifugal force in action in one way or another, whether it be riding on a merry-go-round as a child, spinning a bucket of water upside and observing as the contents hug the insides of the bucket, or watching mud spinning off of a turning tire. In addition to making dizzying carnival rides, this force can be used in the design of many mechanical applications, where it is harnessed to control a variety of effects. One such […]

### Aircraft Landing Gear Mechanism Analysis

##### Fanny Littmarck | July 3, 2013

Aircraft rely on landing gear in order to taxi, take off, and land. The landing gear of your average commercial airplane consists of a shock-absorber cylinder and piston, and a pair of tires. Intuitively, the shock-absorber experiences stresses as the landing gear touches the ground — but how much? In order to design a landing gear mechanism that can withstand many landings, and to determine when it’s time to swap out an old one, we can perform a multibody dynamics […]

### Simulating Plate Heat Exchangers

##### Laura Bowen | June 26, 2013

It’s not always obvious what a major role temperature control plays in modern technology, as the interchange happens in the background. Plate heat exchangers, made up of successions of metal plates and various coiled pipes, regulate and manipulate temperature, and they get the job done quickly — thanks to an active surface that is large with respect to their volume.

### A Multidisciplinary Approach to Electronics Design

##### Andrew Griesmer | June 24, 2013

Sharp is a powerhouse in the electronics industry, involved in televisions, liquid crystal displays, LED lighting systems, solar cells, multi-function business machines, and many other electronics-based products. One of a global network of Sharp R&D laboratories, Sharp Laboratories of Europe (located in Oxford, England), has been busy researching and developing LED lighting, display technology, microfluidic lab-on-a-chip, and energy systems for incorporation into Sharp’s products.

### Thermal Analysis Measures Blistering Heat

##### Laura Bowen | June 18, 2013

If you roast a turkey for dinner and you need to check the temperature, the technology exists to find it. But what happens if the temperature is so hot that a consumer-grade thermometer, or any man-made device, really, would instantly melt and be destroyed? This might not be a common occurrence in your kitchen, but it is a real concern in blast furnaces, where temperatures can reach close to 1,500°C. Simply guessing is far from safe. Luckily, by simulating with […]

### Modeling a Helicopter Swashplate Mechanism

##### Pawan Soami | June 14, 2013

A swashplate mechanism, used in a helicopter to control the pitch of the rotor blades, can be easily simulated using the Multibody Dynamics Module available in COMSOL Multiphysics. This module enables simulation of an assembly of flexible and rigid bodies, together with physical phenomena from fluid, heat, and electrical applications, among others. Here, we will show you a model to convey how a swashplate mechanism works and at the same time analyze the stresses and deformation in the flexible rotor […]

### A Recipe for Induction Stove Design Using Multiphysics Simulation

##### Alexandra Foley | June 10, 2013

When I was little, I used to love spending the night at my grandparents’ house, where I was allowed to watch TV, stay up late, and in the morning, help my grandmother make pancakes. The hardest part was always waiting for her old, slow electric burner to heat up — to my six-year-old self, it seemed to take hours for the burner to become hot enough after we’d finished mixing the batter. Luckily for me, and for other impatient chefs […]

### Structural Mechanics Tutorials: Rigid Connector and Linear Buckling

##### Andrew Griesmer | June 6, 2013

Continuing our structural mechanics tutorial blog series, we have created two more videos of different functionality existing in COMSOL’s Structural Mechanics Module. The first post in the series introduced you to the Structural Mechanics Module via a linear elastic analysis of a bracket, and the following post included two supplemental videos for adding Initial Strain and Thermal Stress to the this model. Next up we have two more “mini-tutorials” — this time outlining the Rigid Connector feature and the Linear […]