## Predicting How Long Coffee Stays Warm in a Vacuum Flask

##### Fanny Griesmer October 26, 2017

Important question: If you pour hot coffee into a vacuum flask, how long will it stay warm? There are two different modeling approaches for studying this scenario, but the more accurate method is also more computationally expensive. Let’s see what they are and when they are appropriate — and hopefully find an answer to the question.

### What Is the Physics Behind a Counterweight Trebuchet?

##### Mats Danielsson October 11, 2017

The trebuchet is a large siege weapon that you might recognize from movies set in the Middle Ages or fantasy worlds. This weapon is built on the idea of converting potential energy into kinetic energy to hurl a projectile over a large distance. Simple as it seems, the trebuchet is a complicated dynamical system. In this blog post, we will build a simplified model of a counterweight trebuchet using the Multibody Dynamics Module and examine some of its design features.

### Analyzing Kelvin Probe Designs with COMSOL Multiphysics®

##### Caty Fairclough October 4, 2017

Kelvin probes provide a nondestructive and contact-free method of measuring the work function differences of various material combinations. These probes can have a variety of designs, including different tip shapes, lengths, and radii. To find an optimal design while minimizing the need for extensive testing, one group of researchers used the COMSOL Multiphysics® software. Here’s what they found…

### Evaluating the Effect of Shell Thickness on Muffler Performance

##### GuestLinus Fagerberg October 3, 2017

Guest blogger Linus Fagerberg from Lightness by Design picks up where he left off in his previous blog post to discuss how radiated sound depends on the shell thickness of a muffler. Here, we discuss different entities for gauging the performance of mufflers. One important parameter is the thickness of the muffler’s casing and how this affects its performance. By performing acoustic-structure interaction simulations, we can see how shell thickness affects muffler performance.

### Studying the Thermal Performance of Phase Change Materials

##### Bridget Paulus September 18, 2017

Maintaining an even temperature for buildings in hot climates often requires a lot of energy. One option for improving thermal performance is by including phase change materials (PCMs) in parts of the building. To study the effectiveness of PCMs in regulating temperature, researchers used the COMSOL Multiphysics® software to model a novel plaster that includes a PCM. They then analyzed the thermal performance of the PCM-enhanced plaster and compared the results with a reference plaster.

### Predicting the Sound Emission of a Muffler Design via Simulation

##### GuestLinus Fagerberg September 14, 2017

Guest blogger Linus Fagerberg from Lightness by Design returns to share a novel approach for predicting external noise generation in muffler designs. In recent years, the European Union has introduced stricter noise emission limits for road vehicles. For those designing mufflers, these limits make it important to create more efficient ways of developing and assessing the performance of their designs. At Lightness by Design, we’ve developed a novel approach that accomplishes this goal.

### Using Simulation to Study Ultrasound Focusing for Clinical Applications

##### GuestThomas Clavet August 31, 2017

Today, guest blogger Thomas Clavet of EMC3 Consulting, a COMSOL Certified Consultant, discusses simulating phased array and geometrically focused probes. Ultrasound focusing is widely used in various industrial applications, such as nondestructive testing (NDT) and medical imaging. For clinical applications, high-intensity focused ultrasound (HIFU) is a specific aspect of this technology where most of the power provided by the probe is carried to a targeted zone to coagulate biological tissues. This blog post discusses ultrasound focusing simulation.

### Analyzing the Acoustics in a Simplified Particulate Filter Model

##### Brianne Christopher August 25, 2017

A leading cause of smog and particulate pollution is the harmful emissions from automobiles, especially those that run on diesel engines. Today, most vehicles with diesel engines are required to install a diesel particulate filter (DPF) to catch carbon-based particulates that are emitted from their exhaust. Using the COMSOL Multiphysics® software, we can analyze the acoustics of a DPF.

### Can a Wine Cooler Actually Keep Your Beverage Cold?

##### Magnus Ringh August 17, 2017

During sunny days, it’s tempting to bring food and drinks outside to enjoy the weather. However, it can be a challenge to keep wine (or any beverage) cold in the heat. Wine coolers supposedly keep chilled beverages cold for at least an hour. In this blog post, we use the COMSOL Multiphysics® software to see how a wine cooler works and whether or not it can keep drinks cool.

### Analyzing a Unique Poroelastic Metamaterial with Simulation

##### Caty Fairclough August 7, 2017

Metamaterials are artificial materials with properties that rely on a particular structural design rather than chemistry. Their structure is often complicated, making these materials challenging to fabricate. Here, we present numerical research that investigates one such material — a poroelastic metamaterial (made from a single material with voids) with the ability to expand under hydrostatic pressure.

### Comparing 2 Approaches for Modeling Electronic Chip Cooling

##### Caty Fairclough August 2, 2017

When designing heat sinks, it’s important to accurately measure their cooling capacity. By modeling heat transfer in these systems, we can calculate the temperature of the electronic components. The modeling approach we use will affect the accuracy of the results and the efficiency of the simulation. In this blog post, we compare two modeling approaches for analyzing electronic chip cooling. We also discuss new features in the COMSOL Multiphysics® software that make it easier to set up heat sink geometries.