Free Surface Computations in Mixers and Rotating Machinery

Ed Fontes | January 26, 2016

The rotation of the impellers in a mixer or stirred reactor creates ripples on the liquid surface when the agitation is moderate. If the ripples are small in comparison to the height of the fluid in the vessel, the shape and height of the free surface can be explicitly calculated from the velocity field in a separate solution step. The latest version of the Mixer Module in COMSOL Multiphysics includes a Stationary Free Surface feature for such computationally inexpensive calculations.


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Nikola Strah | January 25, 2016

Surely you remember the last time you were stuck in bed with the flu. Influenza, commonly known as the flu, can be at the very least an unpleasant experience, but it also claims a lot of casualties every year. Today, public health officials use mathematical modeling techniques to study the flu and other infectious diseases to predict their spread and make informed decisions about public health.


Walter Frei | January 20, 2016

Radiofrequency tissue ablation is a medical procedure that uses targeted heat for a variety of medical purposes, including killing cancerous cells, shrinking collagen, and alleviating pain. The process involves applying mid- to high-frequency alternating current directly to the tissue, raising the temperature in a focused region near the applicator. We can simulate this process with COMSOL Multiphysics and the AC/DC and Heat Transfer modules. In today’s blog post, we will go over some key concepts for modeling this procedure.


Giuseppe Petrone | January 18, 2016

Today, guest blogger and Certified Consultant Giuseppe Petrone of BE CAE & Test discusses creating apps to perform thermal analyses of electronic devices. When manufacturing electronic devices, leading companies often look to simulation in order to thermally characterize their products. At BE CAE & Test, we have found a more efficient way of answering such requests: designing apps that are tailored to our customers’ needs. Our surface-mount device app, presented here, is just one testament to what apps can achieve.


Fabrice Schlegel | January 13, 2016

To accurately compute lift and drag forces and optimize any airfoil following the NACA naming convention, COMSOL Multiphysics version 5.2 includes a new example, the NACA Airfoil Optimization app. In this blog post, we discuss how the app can be used for production applications and how you can benefit from using the Application Builder to enhance your own models and apps.


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Brianne Costa | January 11, 2016

In 2012, guests at a California music festival called Coachella were shocked to see rap artist Tupac Shakur perform onstage. Why? Because the famed musician had been dead for nearly two decades. Viral reactions called the digitized performance a “hologram”, which is actually a misnomer. This stunt is an example of the Pepper’s Ghost optical illusion, which can be explained with ray optics.


Mads Herring Jensen | January 21, 2016

COMSOL Multiphysics version 5.2 introduced a number of new features and functionality, including an acoustics-specific plot type called the Octave Band plot. This plot type provides you with an easy and flexible way to represent any frequency response, transfer function, sensitivity curve, transmission loss, or insertion loss — all of which are essential plots in many acoustics applications. Let’s learn a bit more about the Octave Band plot, while highlighting its various options and settings.


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Edmund Dickinson | January 19, 2016

When studying a system’s chemical kinetics, it’s common to use perfectly mixed batch reactor assumptions and design experiments that keep mixing conditions ideal. Such assumptions include perfectly mixed (ideal tank reactors) and perfectly unmixed (ideal plug flow reactors). In reality, however, it’s rare that all of the reactor’s parts behave the same way. Space-dependent modeling is thus essential in understanding and optimizing chemical reactors. Let’s explore the development of a detailed reactor model, starting with a simple perfectly mixed example.


Daniel Smith | January 14, 2016

I love my Philips Hue lighting system, which I bought over a year ago. The system allows you to set millions of different colors and thousands of brightness levels for up to 18 bulbs using a smartphone. You can also program the system to automatically turn on as you approach your residence, known as geofencing, or at specific times of the day. But how does the light quality compare to that of other lighting technologies?


Nancy Bannach | January 12, 2016

Modeling complex geometries with thin structures can be very costly in terms of computational effort, particularly as such structures require quite a lot of mesh elements in order to resolve them. COMSOL Multiphysics provides dedicated features for modeling thin structures so that such models can be solved efficiently while maintaining accuracy. To set up and postprocess thin structures, COMSOL Multiphysics also provides specialized operators to help you consider all the relevant parameters required for accurate results.


Nirmal Paudel | January 7, 2016

The nonlinear magnetic saturation curves in the AC/DC Module’s Nonlinear Magnetic Materials Database can now be used in frequency-domain simulations using COMSOL Multiphysics version 5.2. You can now convert the associated BH or HB curve, which was previously supported only for stationary and time-dependent studies, into an effective BH or HB curve using the newly added Effective Nonlinear Magnetic Curves Calculator app. In this blog post, we will discuss how this app is used in frequency-domain simulations.


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