General 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 […]
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.
Video: 2D Models from Cross Sections of 3D Geometries
A while back, I blogged about a new feature made available in COMSOL Multiphysics 4.3b, the ability to create 2D models from the cross sections of 3D geometries. We are so excited for this new feature that we decided to make a video showing you how easy it is to use.
Using Curvilinear Coordinates
Curvilinear coordinates are a coordinate system where the coordinate lines may be curved. The new user interface for automatic computation of curvilinear coordinates is a very practical addition to version 4.3b for those working with anisotropic materials in free-form CAD designs. If you have a generic bent shape and try to apply the usual coordinate systems like Cartesian, cylindrical, or spherical, you are out of luck. Curvilinear coordinates are needed to smoothly follow the design, which typically has no mathematical […]