Fluid & Heat Blog Posts
Simulating Viscous Fingering Using Equation-Based Modeling
A prospective user of COMSOL approached me about modeling viscous fingering, which is an effect seen in porous media flow. He hadn’t found a satisfying solution elsewhere, so he turned to COMSOL. I’d like to share with you some of my insight on how to go from idea to model to simulation by taking a “do-it-yourself approach” and utilizing the equation-based modeling capabilities of COMSOL Multiphysics.
Predicting Microwave Drying of Potatoes
You may not think of reheating food in the microwave as a drying process, but as we saw at the COMSOL Conference 2013 Boston, microwave technology — the same technology used in domestic microwave ovens — can be used for drying fruits and vegetables. One poster presented at the conference featured microwave drying of potatoes and how the heat and mass transfer that occurs can be modeled to predict the drying process.
Thermal Modeling of Surfaces with Wavelength-Dependent Emissivity
Whenever we are solving a thermal problem where radiation is significant, we need to know the emissivities of all of our surfaces. Emissivity is a measure of the ability of a surface to emit energy by radiation, and it can depend strongly upon the wavelength of the radiation. This is very relevant for thermal problems where the temperature variation is large or when there is exposure to a high-temperature source of radiation such as the sun. In this post on […]
New Mixer Module Showcases CFD Capabilities of COMSOL
The Mixer Module provides ready-made interfaces for describing the difficult problem of laminar and turbulent flows in rotating machinery with free liquid surfaces. COMSOL has been developing different techniques for modeling CFD, moving geometries, and free surfaces during the past few years for a number of different applications. This has now culminated in the new Mixer Module that was released with version 4.4, and it clearly showcases the improved CFD capabilities of COMSOL.
COMSOL 4.4 Brings Particle-Field and Fluid-Particle Interactions
The trajectories of particles through fields can often be modeled using a one-way coupling between physics interfaces. In other words, we can first compute the fields, such as an electric field, magnetic field, or fluid velocity field, and then use these fields to exert forces on the particles using the Particle Tracing Module. If the number density of the particles is very large, however, the particles begin to noticeably perturb the fields around them, and a two-way coupling is needed […]
Coupling Transport and Solid Mechanics Models for Better Puffed Rice
In my work at COMSOL, it’s always interesting to see how broad the field of heat transfer can be. Far from being limited to steel ingots and CPU fans, researchers often use COMSOL Multiphysics to study heat transfer in food manufacturing. One good example of this is the study of thermal and mechanical effects in the production of puffed rice, which was presented at the COMSOL Conference 2013 in Boston.
Mersen Simulates Joule Heating in Busbars and Fuses
Joule heating is a fairly standard type of simulation for COMSOL users nowadays. It involves solving for electrical voltage and temperature fields simultaneously with highly temperature-dependent material properties. Controlling Joule heating is very important when designing and manufacturing electrical systems components. The electric protection group at manufacturing company Mersen France used to base their busbar and fuse designs on trial-and-error, but these days they turn to COMSOL Multiphysics.
Thermometer Calibration: When Experimentation Falls Short
The International Temperature Scale of 1990 (ITS-90) is the industry calibration standard for measuring temperatures throughout the world. The National Physical Laboratory (NPL) works to establish and maintain the ITS-90 through experiments, most notably, thermometer calibration. To better understand and overcome the shortcomings of the experimental process, Jonathan Pearce, at the UK’s National Physics Laboratory, turned to simulation. His results yielded fascinating results about the microscopic behavior of the liquid-solid interface during the freezing process.