Model How the Bubbles in a Glass of Stout Beer Sink, Not Rise

Fabrice Schlegel | March 17, 2016

When you think of a stout beer, one type that may come to mind is GuinnessĀ® beer. This stout is very special, noticeable by its dark body and famous white head. The dynamics of the foam alone are interesting enough to write a series of blog posts about. Although I don’t drink GuinnessĀ® beer (I’m a fan of IPA), I found the longstanding debate about whether its bubbles are rising or sinking while the beer settles makes an interesting simulation.


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.


Fabrice Schlegel | January 30, 2015

Journal bearings are lubricated components that support a rotating shaft. Cavitation affects the performance of these bearings and must be considered during the design stage. Here, I’ll explain what journal bearings are and why predicting cavitation is important, as well as share an industry example with you.


Fabrice Schlegel | September 26, 2014

There are two aspects of home brewing: the culinary side and the engineering one. Many beer lovers start brewing either to improve a recipe, try to clone their favorite beer, or even simply just to see how it works. After brewing a few batches, however, it turns out that the brewing process can also be very challenging from an engineering point of view.

Fabrice Schlegel | October 28, 2013

Microfluidic devices are so small that the micropumps and micromixers that control and mix the fluid inside the device cannot involve any moving components. Instead, they must take advantage of electroosmotic flow. Here, I will describe the concept of electroosmosis and the electrical double layer (EDL), and how to model these in COMSOL, walking you through two example models.


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.

Fabrice Schlegel | January 27, 2015

If you are interested in using COMSOL Multiphysics software to solve multiphase flow problems, you may be wondering which multiphase flow interface to choose. This is your guide to the six interface options available to you and when you should use them.


Fabrice Schlegel | May 30, 2014

Most numerical simulation methods (finite elements, finite volumes, and finite differences) require stabilization methods when modeling transport applications driven mainly by convection rather than diffusion. With the finite element method (FEM), stabilization means adding a small amount of artificial diffusion. This leads to more robust and faster computational performance. Here, we provide insight on the impact of stabilization on your numerical model. We also look at an alternative numerical method that is very efficient and does not require any stabilization.