Nancy Bannach | April 7, 2014

Fluid flow is involved in many engineering applications. In addition to typical CFD simulations, which replace experiments in wind tunnels, flow must also be considered in the cooling of electronic devices or in the chemical industry, where reacting species are transported by a fluid. COMSOL Multiphysics offers dedicated interfaces for various flow types. When should we use the Laminar Flow or Turbulent Flow interface?

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Valerio Marra | March 18, 2014

What do heated soap bubbles, wavy clouds, and Jupiter’s Great Red Spot have in common? Their formation depends on the dynamics of the shear layer existing between two parallel streams moving at different velocities. This unstable motion, called Kelvin-Helmholtz instability, is ubiquitous and plays an important role in the dynamics of climate, for example. Let’s take a closer look at the onset and evolution of this instability with the help of Computational Fluid Dynamics (CFD) analysis.

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Ahsan Munir | February 26, 2014

DNA is a complex molecule that contains instructions for life and often referred to as a “digital fingerprint” or code telling a cell what to do. DNA is often the only means for accurate testing and identification of biomolecules, cells, or even an entire person during forensic investigations. The need to be able to test for DNA, as quickly as possible, and even at the site where the sample is taken, is becoming more and more important.

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Andrew Griesmer | February 25, 2014

A circulating fluidized bed (CFB) is used to create a homogeneous mixture of gas (usually air) and solid particles to increase the efficiency of the combustion process in boilers. A better understanding of this process will help engineers to optimize their design parameters based on their individual needs. The Circulating Fluidized Bed model in COMSOL does just this, simulating a CFB with a given set of parameters that are easily interchangeable, depending on the needs of the user.

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Alexandra Foley | January 27, 2014

There are, in general, two different types of ventilation systems: mixing ventilation and displacement ventilation. Displacement ventilation is used in large spaces with tall ceilings (at least three meters high), and therefore is mainly found in office buildings, schools, and other public spaces. These higher ceilings allow for upward convective flows exhausting air contaminants, thus resulting in improved air quality. This post explores the simulation of a displacement ventilation system to determine the air temperature and velocity within a room.

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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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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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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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Alexandra Foley | August 21, 2013

Solar photovoltaic (PV) cells are semiconductor devices that directly convert solar energy into electricity or voltage using the photovoltaic effect. These PV cells are more commonly known as solar cells, or solar panels, and in 2012 they produced roughly 93 terawatt-hours (TWh) of electricity — enough energy to power over 20 million homes. Because the cells must be directly exposed to the sun’s rays, they are housed outdoors where the panels are affected by the elements. Therefore, the cells must […]

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