Latest Posts
Using Gradient-Free Optimization
The COMSOL Optimization Module includes both gradient-based and gradient-free optimization techniques. Whereas the gradient-based optimization method can compute an exact analytic derivative of an objective function and any associated constraint functions, it does require these functions to be smooth and differentiable. In this blog post, we examine the use of the gradient-free optimizer, which can consider objective function and constraints that are not differentiable or smooth. The dimensions of a spinning wheel are optimized to reduce the mass while maintaining […]
Simulating the Freeze-Drying Process
When thinking about freeze-drying processes, I am reminded of astronaut food like the freeze-dried ice cream I tried as a kid. While this application of freeze-drying is important for preserving food being launched into space, there is also an incredible number of noteworthy applications that are used a little closer to home. Let’s take a look at the freeze-drying process, how it can be simulated, and some of the products and designs that rely on it to function.
Using a Microfluidic Valve to Separate Charged Particles
When you think of a valve, what is the first thing that comes to mind? Electromagnetic waves, or perhaps, Stokes flow separating charged chemicals in a microchannel system? Maybe neither. The truth is, when researchers try to separate small (in the picoliters region), well-defined sample volumes of chemicals, the dispensing accuracy provided by a mechanical regulator probably won’t suffice. An electrokinetic valve, a type of microfluidic valve, on the other hand, provides the perfect solution by giving researchers the flow […]
Hear About Designing Efficient Appliances from Mieletec FH Bielefeld
In 1898, Carl Miele and Reinhard Zinkann founded the Miele company. Since then, it has grown into one of the world’s foremost producers of household appliances, including washing machines and cooking devices for both domestic and professional use. Miele has created a joint research laboratory, mieletec, with the University of Applied Sciences in Bielefeld, Germany. There, the foundations are being laid for the next generation of resource and energy efficient household appliances. This October, you have the chance to hear […]
Analyzing Electrical and Thermal Conductance in a Contact Switch
A contact switch is used to regulate whether or not an electrical current is passing from a power source and into an electrical device. These switches are found in many types of equipment and they are used to control, for example, the power output from a wall socket into a device when it is plugged in; the currents passing across the circuit board of a computer; or the electricity powering a light bulb when the switch is flipped on. Because of their […]
ETREMA to Talk About Transducer Design using Smart Materials
Julie Slaughter and her team at ETREMA Products are in the enviable position as the sole U.S. provider of the smart material Terfenol-D, and developer of products based on this material. Terfenol-D is said to produce giant magnetostriction that boasts strains 100 times higher than traditional magnetostrictive materials, such as iron. Just imagine the possibilities of applications harnessing this amazing material property. If you’re attending the COMSOL Conference in Boston this October, you will hear ETREMA talk about transducer design […]
Success Stories and Limitations of 3D Printing
From supporting research to creating custom prosthesis, what doesn’t 3D printing seem to promise these days? We all know 3D printing has arrived, and the technology is already being put into practice by companies and tech-savvy consumers everywhere. It seems there’s a new 3D printing success story published every day, and no matter how fascinating, it makes you wonder about the wider repercussions and limitations of 3D printing.
Density-Driven Fluid Flow in Porous Media
There are many different forces that can induce flow in fluids, such as kinetic energy, pressure gradients, concentration gradients, and many more. In natural systems, one effect that can initiate fluid flow in a still fluid is a change in density. This density change will result in a change in the fluid’s buoyancy, thus inciting flow as the denser fluid sinks and the less dense, buoyant, fluid rises. You’re probably most familiar with these changes in density occurring due to […]
Fatigue Prediction Using Critical Plane Methods
Research on fatigue started in the 19th century, initiated following failing railroad axles that caused train accidents. In a rotating axle, stress varies from tension to compression and back to tension in one revolution. The load history is simple because it is uniaxial and proportional. Fatigue can then be evaluated with the S-N curve, also known as the Wöhler curve, which relates stress amplitude to a component’s life. In many applications we deal with multiaxiality and non-proportional loading. In this […]
Acoustics Tutorial for Modeling Organ Pipe Design
The way the sound is shaped as it passes through the pipe of an organ is the result of a carefully calculated and intricate pipe design. Browsing through the Model Gallery, I came across a model of an organ pipe, and it happens to be a great acoustics tutorial for using the Pipe Acoustics, Frequency Domain interface in COMSOL Multiphysics. Let’s talk organ pipe design, and walk through how we can model it with multiphysics software.
Simulating Thermal and Electrical Stresses in Medium Voltage Cables
Underground medium voltage cables are often used to deliver electrical power from a transmission system and into the home of consumers. In the United Kingdom, these cables carry hundreds of amps at voltages between 11 and 33 kV, a typical voltage of electrical transmission cables around the world. Analyzing the stresses that these cables are exposed to over their lifetime is important for ensuring both consumer safety and energy efficiency. Researchers from the Glasgow Caledonian University in Scotland used COMSOL […]
Laser Beam Welding Gets a Magnet Make-Over
Our day-to-day lives are dependent on the safety of technical systems and processes. We blindly trust that reactor vessels withstand the test of time, that the train or ship we’re on does not break down. These metal structures, in turn, rely on accurate welding processes. Here’s where BAM Federal Institute for Materials Research and Testing comes into the picture. BAM researchers have been working on improving upon the high-power laser beam welding process in order to promote safer and more […]
Past, Present, and Future of 3D Printing
There are many necessary steps required in order to create a superior product. Based on some initial (or existing) design, you first need to evaluate the physical characteristics of the system. Once some level of understanding of the system has been obtained, it should then be possible to refine and optimize the design based on some reasonable choice of a figure of merit for a good design. The final stage is to prototype the design, which is where 3D printing […]
Can You Use Heat Transfer to Predict Migration of Contaminants?
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 […]
Report from the Joint CAA-ASA Acoustics Conference
Last month, the Acoustical Society of America (ASA) and the Canadian Acoustical Association (CAA) held the 21st joint meeting of the International Congress on Acoustics (ICA) in Montreal, Canada. This joint congress is one of the major acoustics conferences of 2013, featuring a range of parallel sessions that covered most topics in acoustics. These included, among other things, psycho acoustics, underwater acoustics, transducer modeling, acoustics of musical instruments, nonlinear acoustics, and many more. This year’s acoustics conference also featured a […]
Simulating an Engine Governor, the Spring Loaded Centrifugal Governor
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 […]
Keynote Speaker from Philips to Talk about Pulmonary Drug Delivery
Philips Research Laboratories, located in Eindhoven, is often considered to be an incubator of ideas. The prestigious institute has traditionally been the core of all new product developments at Philips, and many of their forefront discoveries were made here. In October, Senior Scientist Alwin Verschueren of Philips Research Laboratories will hold a keynote talk on pulmonary drug delivery at the COMSOL Conference Rotterdam 2013.
Aircraft Landing Gear Mechanism Analysis
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 […]
The Physics of Sailing, a CFD Analysis
Of all boats, I find sailboats to be the most fascinating, especially when sails are their only means of propulsion. Kinetic energy is transferred from the wind to the sails, which results in a lift force that balances drag forces and allows the sailboat to move through the water. We are all familiar with the parts of a boat above the waterline: deck, spars, sails, and the rudder used to turn the boat (figure 1c). Not everyone pays attention to […]
A Lithium-ion Battery Analysis at INES-CEA
During my time as a PhD student, a blue “Chemical Landmark” plaque was fitted to the building a couple of hundred yards down the road from my lab. The plaque commemorates the achievements of the researchers who made the lithium-ion (Li-ion) battery viable. Whether or not you know about the electrochemistry of rechargeable lithium-ion batteries, you probably rely on one. We carry them around in our phones and laptops, and ride in cars and planes that use them for power. […]
Simulating Plate Heat Exchangers
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.
How to 3D Print COMSOL Models
Quite often we get asked the question “can I 3D print my COMSOL model?” Well, as of version 4.3b, the answer is “yes!” This is because it is now possible to export geometries and meshes as STL files, which is one of the standard file formats for 3D printing. This allows for rapid prototyping of designs; there is no need to outsource parts to machine shops. It is quite remarkable that you could conceive, simulate, optimize, and prototype a design […]
A Multidisciplinary Approach to Electronics Design
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.
Quick Intro to Permanent Magnet Modeling
I’ve written several blog entries involving permanent magnets, in one way or another. Reading those may have raised the question “what about a more simple introduction to permanent magnet simulations?” Fair enough, here’s how to model a permanent magnet and its surrounding magnetic field.