Fluid

Alexandra Foley | December 19, 2013

A while back, I had the opportunity to speak with Steven Conrad, a critical care physician at the Louisiana State University (LSU) Health Science Center in New Orleans. Not only is Dr. Conrad a physician as well as a professor at LSU, he’s also a biomedical engineer who uses finite element analysis (FEA) to conduct research on the design of dialyzers. Dr. Conrad uses COMSOL Multiphysics to gain a deeper understanding of the physics behind these devices, and to create […]

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David Kan | December 18, 2013

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.

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Phil Kinnane | December 6, 2013

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.

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Alexandra Foley | November 7, 2013

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 […]

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Fabrice Schlegel | October 28, 2013

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.

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Alexandra Foley | October 1, 2013

Laminar static mixers are used for the accurate mixing of fluids (both liquid and gas). Unlike a mixer containing moving blades, a static mixer contains twisted stationary blades that are positioned at different angles throughout the cylindrical flow channel of the mixer. When a fluid is pumped through the channel, the alternating directions of the cross-sectional blades cause the fluid to become mixed as it passes along the length of the channel. This mixing technique allows for precise control over […]

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Walter Frei | September 16, 2013

COMSOL Multiphysics offers several different formulations for solving turbulent flow problems: the Spalart-Allmaras, k-epsilon, k-omega, Low Reynolds number k-epsilon, and SST models. All of these formulations are available in the CFD Module, and the k-epsilon and Low Reynolds number k-epsilon are available in the Heat Transfer Module. This posting outlines the reasons why we want to use these various turbulence models, how to choose between them, and how to use them effectively. Throughout the post, you’ll find links to relevant […]

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Alexandra Foley | September 11, 2013

Shell and tube heat exchangers are one of the most widely used type of heat exchanger in the processing industries (65% of the market according to H. S. Lee’s book, Thermal Design) and are commonly found in oil refineries, nuclear power plants, and other large-scale chemical processes. Additionally, they can be found in many engines and are used to cool hydraulic fluid and oil. There are a variety of different configurations for these heat exchangers, but their basic concept can […]

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Laura Bowen | August 29, 2013

When it comes to recreational water sports, simulation can make a dramatic difference in performance. Skimboards are a perfect example of this. These short, thin boards are similar to surfboards without fins and they allow riders to float on the water’s surface and glide. In order to improve the design of the board, one group of researchers relied on hydrodynamics to understand the interaction between water and skimboards.

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Fanny Littmarck | August 27, 2013

Plate heat exchangers have a larger surface with respect to their volume as compared to a conventional shell and tube design, making for an efficient temperature regulation device. As the name infers, these types of heat exchangers consist of layers of corrugated metal forming channels in between. In order to optimize their performance, you need the flow through the channels to be well-distributed. As you can imagine, the flow is very detailed and modeling it can be computationally demanding, if […]

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Alexandra Foley | August 22, 2013

There are many different routes through which drugs and other medications can be delivered into a patient’s body during treatment. These include topographical ointments, pills, vaporizers, and injection systems, among others. Many of these drug delivery systems require an enormous amount of precision when it comes to the location, timing, concentration, and amount of the drug to be administered. This is where simulation can be a big help, as it can allow for the modeling of each of these aspects […]

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