General Blog Posts
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 […]
Mesh Refinement for Wave Problems
This week we are happy to have Kyle Koppenhoefer of AltaSim Technologies as a guest blogger. As COMSOL Certified Consultants, AltaSim can share valuable insights into using the software — today on the topic of meshing wave problems. As part of our efforts to assist COMSOL users in performing high-quality analysis, we recently used our bi-monthly email to remind users to include twelve degrees of freedom per wavelength when meshing wave problems. This article builds on our previous advice. Wave-type […]
Equation-Based Modeling, a Custom Model of a Beating Heart
Equation-based modeling is one of the great strengths of COMSOL Multiphysics. The ability for you to easily access the equations describing the physics you are working with, and adding or manipulating them as you see fit, dramatically opens up the realm of possibilities that you can achieve through modeling and simulation. This is exemplified by the following custom model of a beating heart.
Sweep Your Meshes with Ease
Swept meshing is a geometry discretization technique available in COMSOL Multiphysics for specific types of geometries, including thin geometries, geometries with bends, and models with little or no variation in a specific direction. A swept mesh starts at a source boundary and sweeps along to a specified destination boundary. In previous versions of COMSOL Multiphysics, the source and destination boundaries generally needed to be specified by the user. However, in the latest release, COMSOL Multiphysics version 4.3b, the swept mesh […]
Creating 2D Models from 3D Geometries in COMSOL Multiphysics
Our newest release, COMSOL Multiphysics version 4.3b, contains so many new modules and features, certain additions might get lost in the fray. One addition to the COMSOL Multiphysics base package we don’t want you to miss is the ability to create 2D models from cross sections of 3D geometries. This easy-to-use feature allows engineers to simplify the model, gain understanding of and fine-tune parameters, and dramatically reduce simulation time.
On Solvers: Benefits and Limits of Solution Methods
This week we have the honor of having Professor Wolfgang Joppich as a guest blogger. As you may know, COMSOL Multiphysics provides great default solvers for all applications. For the interested user, it is good to know that you can optionally tune or completely change the solver settings. We strongly recommend that you read this blog posting to get an experts’ perspective on the solver technologies offered by COMSOL. I am an avid reader of the COMSOL Blog and an […]
How to Model Multiphysics in Multimaterial?
Dr. Raj Thiagarajan is a prolific producer of interesting research articles ranging from waste-water treatment to acoustics metamaterials, and lots in between. As the Managing Director at ATOA (“Atom TO Application”) Scientific Technologies, a COMSOL Certified Consultant, Raj has had to simulate all types of applications. Now he will show you how to use multiphysics simulations in multimaterial and composite product design.
Meshing and Optimization in Engineering Magazines
Online engineering magazines, like Design World and Desktop Engineering, are great for anyone out there interested in emerging technologies. I especially liked a few recent articles: two in Design World’s “CAE Solutions” section and one in Desktop Engineering’s simulation section, detailing a couple of major topics important to finite element analysis, or FEA. First there is meshing, the foundation of FEA software. Second, there is optimization, which is all about maximizing efficiency and improving results. The key for any production […]
Using Point Cloud Data in Your COMSOL Model
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.
Probing Your Simulation Results
For a transient simulation, imagine if you could simply insert a virtual sensor in a model at a certain location and then monitor the evolution of a field value over time while solving. In COMSOL Multiphysics® you can do just that by using Probes. You define a probe in the Model Builder tree right under the Model Definitions node. Measuring the value at a point is not the only thing you can do with probes, but in this blog post we […]
What Is COMSOL Multiphysics?
You may be wondering “What is COMSOL Multiphysics?” In short, COMSOL Multiphysics is a comprehensive simulation software environment for a wide array of applications, but structured and user-friendly for all to use. The best way to answer the question of what our software can do is to show you. This is why we have created a video that gives you a brief overview of the capabilities you can possess with the software in your hands.
Introduction to COMSOL Multiphysics, a Book to Get you Started
What does it take to get started using COMSOL Multiphysics? Of course, it depends on where you set the bar. However, grasping the workflow and handling the basic tools can be relatively easy to pick up. To make this process even smoother, first-time users will benefit from the recent major update of the COMSOL Multiphysics instruction manual. The book, Introduction to COMSOL Multiphysics, is a valuable tool for learning COMSOL simulation software and the new version is now available for […]
Metamaterials Make Physics Seem Like Magic
Metamaterials are a new and emerging technology with vast potential to reshape our views on what is and isn’t possible in this physical world of ours. Unlocking the mysteries and overcoming the obstacles associated with metamaterials would lead to a host of technological advances once thought impossible by even the most imaginative of individuals. From making computer chips smaller and faster than the most advanced current ones, to protecting structures from earthquakes, to developing imaging technology that doesn’t harm tissue […]
Multiphysics versus FEA
In a popular post from last year, I discussed accessing and manipulating the underlying equations in COMSOL. This blog post instigated reader comments, and most of the respondents appreciated, or even required, the ability to look at the mathematical model (i.e., equations) behind the physics. While considering this, I realized that there is more to the story, and with a little perspective, the community could benefit from further discussion.
On Solvers: The V-Cycle Multigrid
As discussed previously on the blog, iterative methods efficiently eliminate oscillatory error components while leaving the smooth ones almost untouched (smoothing property). Multigrid methods, in particular, use the smoothing property, nested iteration, and residual correction to optimize convergence. Before putting all of the pieces of this proverbial puzzle together, we need to introduce residual correction and dive a bit deeper into nested iteration. Let’s begin with the latter of these elements.
On Solvers: Multigrid Methods
Solution methods are a valuable tool for ensuring the efficiency of a design as well as reducing the overall number of prototypes that are needed. In today’s blog post, we introduce you to a particular type of method known as multigrid methods and explore the ideas behind their use in COMSOL Multiphysics.
Equations: Who Needs Them?
Most of us take mathematical modeling for granted. After all, we’re taught physics and calculus almost hand-in-hand. But we owe a lot to the early pioneers like Isaac Newton, who demonstrated and strongly promoted interpreting natural phenomena through equations. Differential equations are especially useful since most things change as time marches on. Since we live in 3D space, partial differential equations (i.e., equations that express change in more than one “direction”) arise as the prominent tool to express continuum level […]
User Tip: All About Icons
I give a lot of COMSOL workshops — about 20 so far this year. These are great events and they include hands-on minicourses, which allow me to connect with the audience. One topic that I often spend a few minutes on might surprise you: icons. The icons, especially those found at the nodes in the Model Builder, are packed with useful information. They’re easy to miss because they’re small, but knowing what they mean can be a big help.
Moore’s Law for Solvers
At the heart of any simulation software are the solvers. Those are things that take geometry/mesh/physics to the computational results. While it’s convenient to think about solvers in terms of the type of study (think time-dependent, parametric, or eigenvalue), there is a hierarchy of solvers that are usually employed. And at the foundational level of any simulation — and for every iteration — there is a linear solver.
Multiphysics Makes Single-Physics Simulations Better
Coupled physics phenomena (like electrical heating, fluid structure interaction, and conjugate heat transfer) demand multiphysics, which I’ve written about previously in “What is Multiphysics?”. But what if you just have a simple analysis to do — one that has been simplified to the point where only a “single physics” (to coin a term) is considered? What benefits does multiphysics have for this?