General Blog Posts
How to Identify and Resolve Singularities in the Model when Meshing
In our previous post on Meshing Considerations for Linear Static Problems, we found that, in the limit of mesh refinement, the solution to the finite element model would converge toward the true solution. We also saw that adaptive mesh refinement could be used to generate a mesh that would have smaller elements in regions where the error was higher, rather than simply using smaller elements everywhere in the model. In this post, we will examine a couple of common pitfalls […]
Meshing Considerations for Linear Static Problems
In this blog entry, we introduce meshing considerations for linear static finite element problems. This is the first in a series of postings on meshing techniques that is meant to provide guidance on how to approach the meshing of your finite element model with confidence.
Solving Linear Static Finite Element Models
In this first blog entry of our new solver series, we describe the algorithm used to solve all linear static finite element problems. This information is presented in the context of a very simple 1D finite element problem, but is applicable for all cases, and is important for understanding more complex nonlinear and multiphysics solution techniques to be discussed in upcoming blog posts.
Intro to Piezoelectric BAW Resonator Modeling
If you are using a cell phone, GPS, Bluetooth, or WiFi, chances are that they all have BAW resonators working inside them. All wireless electronic equipment use RF filters to help narrow down the frequency range they should operate within. With thousands of devices working within closely-packed radio frequencies, it is becoming increasingly important to design filters that would be able to reduce interference from unwanted frequencies, boost the signal-to-noise ratio, and lower insertion loss. Doing so may lead to […]
Using Global Equations: Modeling Room Air Temperature in a House
An interesting question came up the other day that I felt would make an excellent blog post since it allows us to discuss one of the very powerful, and often underutilized, features of COMSOL Multiphysics: the Global Equation. In this post, we will look at using global equations to introduce an additional degree of freedom to a model. This additional degree of freedom will represent something we do not want to model explicitly.
How to Implement a Mesh Refinement Study
A couple of weeks ago, I led a webinar on postprocessing and visualization features in COMSOL Multiphysics. This webinar was very popular among COMSOL users, so I wanted to follow up with a blog post to highlight one of the important topics we covered — performing a mesh refinement study in COMSOL Multiphysics.
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 […]
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 […]