All posts by Walter Frei

Walter Frei | September 16, 2013

COMSOL Multiphysics offers several different formulations for solving turbulent flow problems: the L-VEL, yPlus, Spalart-Allmaras, k-epsilon, k-omega, Low Reynolds number k-epsilon, and SST models. All of these formulations are available in the CFD Module, and the k-epsilon and Low Reynolds number k-epsilon are available in the Heat Transfer Module. This posting outlines the reasons why we want to use these various turbulence models, how to choose between them, and how to use them effectively. Throughout the post, you’ll find links […]

Read more ⇢

Article Categories

Walter Frei | September 10, 2013

A question we get asked all of the time is: “Which of the COMSOL products should be used for modeling a particular electromagnetic device or application?” There are currently six modules labeled as “Electrical” in the product suite; the AC/DC Module, RF Module, Wave Optics Module, MEMS Module, Plasma Module, and Semiconductor Module. The first four address applications purely governed by various forms of Maxwell’s equations, while the Plasma Module addresses the coupling of electromagnetic fields to plasma transport and […]

Read more ⇢

Article Categories

Walter Frei | August 30, 2013

Recently, I was given a copy of the book Finite Element Modeling Methods for Photonics, by B.M. Azizur Rahman and Arti Agrawal. This book proved to be a good companion to the RF Module and Wave Optics Module for graduate students starting in photonics and new users of COMSOL who would like a very targeted introduction to the field. The website accompanying the book comes with some sample computer codes used by the authors in simulation that readers can use […]

Read more ⇢

Article Categories

Walter Frei | August 23, 2013

The COMSOL Conference 2013 will be a great opportunity for you to learn about the use of the COMSOL Multiphysics® family of products. Today, I’ll talk a little bit about the various minicourses, how they fit together, and how you can decide which minicourses to attend.

Read more ⇢

Article Categories

Walter Frei | August 2, 2013

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 […]

Read more ⇢
Walter Frei | June 20, 2013

The Coplanar Waveguide (CPW) is commonly used in microwave circuits. COMSOL Multiphysics, with the RF Module, makes it easy to compute the impedance, fields, losses, and other operating parameters needed when designing a CPW.

Read more ⇢

Article Categories

Walter Frei | April 2, 2013

A question that comes up occasionally is whether or not you can compute the inductance of a single straight wire. This seemingly simple question actually does not really have an answer, and gives us the opportunity to talk about a very interesting point when solving Maxwell’s equations. Anybody working in the field of computational electromagnetics should have an understanding of this key concept, as it will help you properly set up and interpret models involving magnetic fields.

Read more ⇢

Article Categories

Walter Frei | March 20, 2013

There is sometimes a need to include data from other simulation packages into a COMSOL Multiphysics model. There are a variety of ways in which this can be done, but one of the easiest approaches is to read in the point cloud data via a spreadsheet format text file. In this blog post, we walk through the steps of reading in such data, and using it in a COMSOL model.

Read more ⇢

Article Categories

Walter Frei | July 9, 2012

A new series of courses addressing the fundamentals of the software independent of physics is to be introduced at the COMSOL Conference 2012 in Boston and Milan. These minicourses include solvers, optimization, meshing, post-processing, and equation-based modeling.

Read more ⇢

Article Categories

1 2 3 4