Blog Posts Tagged Technical Content
How to Use Numeric Ports in Your RF Analyses
When performing RF analyses in the COMSOL® software, you can use numeric ports to compute the mode of a port with an arbitrary shape. This demonstration includes a waveguide adapter example.
How to Implement the Weak Form for Time-Dependent Equations
Here’s a comprehensive equation-based modeling guide on how to implement the weak form for time-dependent equations, including theoretical background and step-by-step instructions.
RF Signal Transformation Between the Time and Frequency Domains
Want to make your RF and microwave device modeling more efficient? Read this blog post to learn how to implement the fast Fourier transform in your simulations.
Image Denoising and Other Multidimensional Variational Problems
Learn how to solve variational problems featuring multiple dimensions, higher-order derivatives, and multiple unknowns with a fun example: image denoising in a grainy photograph.
Methods for Enforcing Inequality Constraints
Learn 2 methods for enforcing inequality constraints in your variational problems, the Lagrange Multiplier method and Augmented Lagrangian method, as well as the theory behind them.
Methods for Dealing with Numerical Issues in Constraint Enforcement
This post is helpful if you use equation-based modeling: Learn a variety of different methods for dealing with numerical issues when enforcing constraints in variational problems.
Specifying Boundary Conditions and Constraints in Variational Problems
In part 2 of a blog series on solving variational problems in COMSOL Multiphysics®, we discuss how to specify general boundary conditions and constraints.
How to Model the Compression of a Hyperelastic Foam
When characterizing hyperelastic materials, how do you ensure accuracy? Here, we show how to model the compression of a sphere made of an elastic foam using experimental data.
Introduction to Modeling Soap Films and Other Variational Problems
In this introduction to a 5-part series, learn how to solve variational problems using equation-based modeling, which is useful for modeling soap films, catenary cables, light beams, and more.
How to Model Ion-Exchange Membranes and Donnan Potentials
Get an introduction to the theory behind the Nernst-Planck-Poisson equations, Donnan potentials, and how to model ion-exchange membranes in batteries and fuel cells.
How to Model Sparging in COMSOL Multiphysics®
Sparging, the process of bubbling a gas into a liquid, is seen most notably in carbonation, such as for soda and seltzer water. This mass transfer process can be modeled in COMSOL Multiphysics®.
How to Place Inlet and Outlet Boundary Conditions in CFD Simulations
When setting up fluid flow simulations, at what distance can we apply boundary conditions without interfering with the process? Here, we discuss how to place inlet and outlet boundary conditions.