Describing Viscoelastic Behavior with an Oldroyd-B Benchmark

Brianne Costa July 31, 2018

The Oldroyd-B numerical model defines flow in fluids that exhibit complex viscoelastic behavior under strain, such as clay, toothpaste, oil, and polymer solutions. In a benchmark model of an Oldroyd-B fluid, the COMSOL Multiphysics® software and add-on CFD Module are used to solve the numerical model, the results of which have been validated by published research.

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Bridget Paulus July 30, 2018

From home HVAC systems to spacecraft ejectors, diffusers find use in all kinds of applications. For example, diffusers are often used in supersonic aircraft like ramjets to slow down fluid flow and increase static pressure. To design transonic diffusers for supersonic applications, engineers must account for factors like high-speed turbulent flow and shock waves. As this benchmark model illustrates, these complex phenomena can be accurately analyzed using the COMSOL® software.

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Nathan Martin July 17, 2018

Following up on a previous blog post about glacier flow modeling, we are going to delve a bit further into a crucial component of geophysics modeling in general: parameterizing numerical models using observations. Let’s see how we can quantify sensitivity and infer unknown parameters through indirect observations using the COMSOL Multiphysics® software and add-on Optimization Module.

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Brianne Costa July 4, 2018

Multijet tubular reactors are used to manufacture polymers such as polyester. The turbulent flow that occurs in this type of reactor can affect the manufacturing process, including the reaction kinetics, fiber quality, conversion, and yield. By developing a reactor model that fully takes into account both the fluid dynamics and chemical reactions, you can optimize a reactor design for efficient and reliable polymer production.

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Brianne Costa June 25, 2018

In the 1998 song “This Kiss”, country singer Faith Hill describes the way she feels for the person she loves as “centrifugal motion”. Either Hill wants to get away from the song’s subject ASAP or she mixed up the term centrifugal with centripetal. We’ll forgive the 20-year-old song’s inaccuracies — besides, understanding the effect of centrifugal force is more important when designing components in a wide range of industries, such as centrifugal pumps for automotive applications, than in songwriting.

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Christian Wollblad June 13, 2018

We have already discussed the factors that make a high-quality mesh and how to prepare a CFD model geometry for meshing. In this follow-up blog post, learn about physics-controlled meshing, adaptive mesh refinement, and how to use a variety of meshing tools in the COMSOL Multiphysics® software for your fluid flow simulations.

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Christian Wollblad June 11, 2018

The quality of a computational fluid dynamics (CFD) model is often determined by the quality of the mesh used to solve the problem. A good mesh facilitates convergence, reduces memory requirements, and results in accurate solutions. It is therefore worthwhile to invest time and thought into creating the mesh when solving a CFD problem. In this blog post, we describe the factors of a quality mesh and how to prepare a fluid flow model geometry for meshing.

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Ed Fontes June 6, 2018

The Adidas® Telstar® soccer ball is the official ball of the 2018 FIFA World Cup™, and the Nike® Ordem V soccer ball is used in the seven largest national leagues in Europe, including the top three: the Spanish La Liga, the English Premier League, and the Italian Serie A. Previously, we discussed an experimental setup for measuring the terminal velocity of these two soccer balls to see if there’s a difference that could affect player performance. Here’s what we found…

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Thomas Forrister June 5, 2018

The greenhouse effect has made it necessary for scientists to develop combustion processes that minimize the accumulation of carbon dioxide in the atmosphere. Possible fuels in these processes include biomass and other biofuels, which recycle carbon within a short timescale. But there’s a downside: Combustion of these materials produces carbon and ash particles that must be removed from the exhaust. To improve particle filtration, researchers studied electrostatic filter designs using models that were validated by comparing them to experimental data.

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Ed Fontes June 1, 2018

Every four years, people interested in association football/soccer (a few billion people) talk about the FIFA World Cup™. We at COMSOL are no exception. During coffee breaks and lunches, we are discussing the different teams, players, preparations, and the tiny details that might impact the teams. The ball is an important protagonist of the games. The subject of the ball combines our passion for soccer and physics into one discussion!

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Ed Fontes May 31, 2018

In a previous blog post, we discussed using field-based methods (level set and phase field) for modeling free surfaces. Another option, moving mesh, can handle free liquid surfaces that do not undergo topology changes. In this blog post, we will demonstrate how to use the moving mesh method for modeling free surfaces and compare the results with field-based methods.

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