Fluid & Heat Blog Posts
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.
Exploring the Leidenfrost Effect
The Leidenfrost effect, also known as film boiling, occurs when a liquid comes into contact with a solid that is at a temperature well above the liquid’s boiling point. Upon contact, a layer of vapor forms between the liquid-solid interface, creating a barrier between the two. There are many examples of this phenomenon, ranging from something you may have seen in your kitchen (water “dancing” around in a pan) to things you shouldn’t try at home (dipping your hand into […]
Learn about Modeling Vacuum Systems in COMSOL
Until recently, simulation had not been widely used by vacuum system designers because of an absence of commercial simulation tools. Last October, my colleague James Ransley held a webinar about how to model vacuum systems using COMSOL Multiphysics. The webinar was a great success, and it inspired us to produce a dedicated product for modeling vacuum applications: the Molecular Flow Module (new with version 4.3b). This year, on November 21st, James will be giving a webinar explaining the new features […]
Modeling Electroosmotic Flow and the Electrical Double Layer
Microfluidic devices are so small that the micropumps and micromixers that control and mix the fluid inside the device cannot involve any moving components. Instead, they must take advantage of electroosmotic flow. Here, I will describe the concept of electroosmosis and the electrical double layer (EDL), and how to model these in COMSOL, walking you through two example models.